Article ID: CJ-21-0959
Background: This study aimed to elucidate the short-term surgical outcomes and hemodynamics of the Intuity valve compared to the standard bioprosthesis in Japanese patients.
Methods and Results: Among the 307 consecutive patients who underwent aortic valve replacement (AVR) between February 2019 and March 2021, the Intuity valve was implanted in 95 patients (Intuity group) and a conventional stented bioprosthesis was implanted in 193 patients (conventional group). After propensity score matching, there was no significant difference in in-hospital mortality between the Intuity (n=2, 3%) and conventional groups (n=0, P=0.490). Operation, cardiopulmonary bypass, and aortic cross-clamping times were significantly shorter in the Intuity group. Although the effective orifice area index, trans-prosthetic mean pressure gradient, and peak velocity were similar between the 2 groups at 1 week postoperatively, the Intuity group showed a better mean pressure gradient and peak velocity at 1 year postoperatively. Complete atrioventricular block requiring permanent pacemaker implantation developed in 2 patients (3%) in the Intuity group and none in the conventional group (P=0.476). Mild or greater paravalvular leakage was present in 8 patients (13%) in the Intuity group and 2 patients (3%) in the conventional group (P=0.095).
Conclusions: AVR using the Intuity valve in Japanese patients is satisfactory, with a better valve performance and a low incidence of complete atrioventricular block at 1 year postoperatively.
Although surgical aortic valve replacement (AVR) is the standard treatment for severe aortic stenosis, transcatheter aortic valve replacement has emerged as an alternative, and has been established as the first-line treatment for high-risk patients.1–3 Therefore, the minimization of invasion during surgical AVR is warranted. The Edwards Intuity valve system (Edwards Lifesciences, Irvine, CA, USA) is a rapid deployment aortic valve, which is used to facilitate minimally invasive surgery and reduce procedural and implant times.4 The Intuity valve system resulted in good postoperative hemodynamics and reduced cross-clamping time, but has increased the risk of postoperative pacemaker implantation.5–8 This evidence is mostly reported in Western countries, where most patients have larger body sizes than the Japanese. A smaller body size is known to be a risk factor for in-hospital mortality and adverse outcomes after AVR because of the smaller size of the prosthetic valves, a higher technical difficulty due to smaller anatomy, or complications related to cardiopulmonary bypass, such as hemodilution or transfusion requirements.9,10 The hemodynamic benefits of the Intuity valve system in Japanese patients remain unclear. This study aimed to elucidate the short-term surgical outcomes and hemodynamics of the Intuity valve compared to the standard bioprosthesis in Japanese patients.
Among 307 consecutive patients who underwent AVR from February 2019 to March 2021, 288 patients were implanted with biological valves. Of these, 95 patients were implanted with the rapid deployment Intuity aortic valve (Intuity group), whereas 193 patients were implanted with conventional stented biological valves (conventional group): Inspiris (Edwards Lifesciences, Irvine, CA, USA; n=97, 50.3%), Avalus (Medtronic, Minneapolis, MN, USA; n=90, 46.6%), Mosaic (Medtronic; n=5, 2.6%), and Crown (LivaNova, London, UK; n=1, 0.5%). The general exclusion criteria for rapid deployment of AVR at our institution were pure aortic valve regurgitation and aneurysm of the aortic root and/or ascending aorta. Infective endocarditis, complete right bundle branch blocks, and Sievers type 0 bicuspid aortic valves were treated as relative contraindications. In the Intuity group, 1 case was excluded due to procedural failure; the patient with aortic valve regurgitation had a severe intraoperative paravalvular leakage (PVL); subsequently, the Intuity valve was re-implanted with 12 pairs of pledgeted mattress sutures.
The study was conducted in accordance with the Declaration of Helsinki and approved by the ethical committee of our hospital (Institutional Review Board Number: M30-026-4); opt-out consent was obtained instead of individual written informed consent due to the retrospective nature of the study.
AVR SurgeryAVR was performed through median sternotomy (n=249) or right mini-thoracotomy (n=38) with tepid hypothermic cardiopulmonary bypass. After standard aortotomy, the native aortic valve leaflets were excised, and calcium debridement of the annulus was performed. For the conventional valves, the valve size was determined according to the manufacturers’ sizers to fit comfortably in the supra-annular position. Pledgeted non-everting mattress sutures were used in the annulus, and the valve was sewn into the supra-annular position. For the Intuity valve, the size was determined with a cylinder slightly resistant to pass through, and contrarily, the flange could not pass through the aortic annulus. The implantation method used for the Intuity valve was based on previous reports.11,12 In brief, 3 equidistant guiding sutures were placed through the nadir of the aortic annulus and then placed in corresponding positions through the sewing ring of the Intuity valve. Using the guiding sutures, the valve was lowered onto the annulus and secured in position under direct vision. The balloon catheter was then inflated to deploy the stent frame. The inflation pressure and time were 4.5 atm and 10 s, respectively. Finally, 3 guiding sutures were tied. In the case of a standard stented biological valve, the aortic prosthetic valve was implanted using non-everting mattress stitches in a supra-annular position. The choice of the prosthetic valve was mainly at the discretion of the surgeon.
Echocardiographic ParametersTransthoracic echocardiography was routinely performed by experienced medical technologists before surgery, 1 week and 1 year postoperatively, and every year thereafter. The effective orifice area (EOA) and trans-native or trans-prosthetic aortic valve mean pressure gradients (MPGs) were calculated using the continuity and Bernoulli equations, respectively. The EOA index (EOAI) was calculated by dividing the EOA by the body surface area. Left ventricular mass (LVM) was calculated using the echocardiographic linear method and indexed to the body surface area (LVMI).13
Postoperative Management and Follow upAll patients received anticoagulation therapy with warfarin once adequate hemostasis was achieved. Patients received warfarin for the first 3 months, with a target international normalized ratio of 2.0–2.5 unless the patients had other medical conditions that required anticoagulant therapy, such as atrial fibrillation. Follow-up data after the operation were obtained through a review of patient medical records and telephone or postal mail interviews. The mean follow-up period was 14.8±8.7 months in the Intuity group and 14.2±8.1 months in the conventional group.
Definitions and EndpointsMajor adverse cardiac and cerebrovascular events (MACCEs) were defined as sudden death, cardiac-related death, myocardial infarction, cerebrovascular accidents, and cardiac arrhythmia requiring an implantable pacemaker or cardioverter defibrillator. Chronic kidney disease was defined as stage III, IV, or V according to the clinical practice guidelines for the evaluation and management of chronic kidney disease.14 Severe prosthesis-patient mismatch (PPM) was defined as an EOAI ≤0.65 cm2/m2.15 The study endpoint was the early outcomes of AVR using the Intuity valve compared with conventional valves. As a subgroup analysis, the outcomes were also investigated in selected patients who underwent isolated primary AVR.
Propensity Score Matching and Statistical AnalysisThe propensity score was used to match patients from each group and was estimated using logistic regression with covariates including age, sex, aortic valve etiology, bicuspid aortic valve, hemodialysis, combined operation, and the Society of Thoracic Surgeons risk score. The matched cohort was created by matching patients from each group using a caliper width equal to 0.2 of the standard deviation of the propensity score logit.16 Continuous variables with a normal distribution were presented as mean±standard deviation, whereas categorical variables were presented as frequencies and percentages. Unpaired or paired Student’s t-test were used to analyze continuous variables with normal distributions, and Fisher’s exact test and the chi-squared test were used to assess categorical variables. Statistical analyses were performed using R version 4.0.3 (R Foundation for Statistical Computing, Vienna, Austria). Statistical significance was set at P<0.05.
The patient characteristics are summarized in Table 1. In the unmatched cohort, the mean age was higher in the Intuity group (75±6 years) than in the conventional group (69±12 years) (P<0.001). Male patients were less common in the Intuity group (n=41, 44%) than in the conventional group (n=115, 60%, P=0.015). The body surface area was smaller in Intuity group (1.55±0.17 m2) than in conventional group (1.62±0.22 m2, P=0.006). A majority of Intuity valves were implanted for cases of aortic stenosis or combined aortic stenosis with regurgitation, except in 1 case where it was implanted for pure aortic regurgitation related to endocarditis. The bicuspid valve was less frequent in the Intuity group (n=10, 11%) than in the conventional group (n=64, 33%, P<0.001). Complete right bundle branch block was diagnosed in 9 patients (10%) in the Intuity group and 19 patients (10%) in the conventional group (P=1.000). Patients with chronic kidney disease and hemodialysis were more frequent in the Intuity group than in the conventional group. The Society of Thoracic Surgeons risk score was higher in the Intuity group (5.5±6.4) than in the conventional group (3.7±4.4; P=0.005). Among the matched cohorts, patient backgrounds were comparable between the 2 groups. Preoperative echocardiography findings, including left ventricular end-diastolic and end-systolic dimension, left ventricular ejection fraction, and severity of aortic valve stenosis, were also similar between the 2 groups in the matched cohort.
| Unmatched cohort | Matched cohort | |||||
|---|---|---|---|---|---|---|
| Intuity (n=94) |
Conventional (n=193) |
P value | Intuity (n=65) |
Conventional (n=65) |
P value | |
| Age (years) | 75±6 | 69±12 | <0.001 | 74±7 | 74±3 | 0.960 |
| Male (%) | 41 (44) | 115 (60) | 0.015 | 30 (46) | 28 (43) | 0.860 |
| Body surface area (m2) | 1.55±0.17 | 1.62±0.22 | 0.006 | 1.56±0.18 | 1.57±0.19 | 0.605 |
| Aortic valve etiology (%) | ||||||
| Stenosis | 68 (72) | 76 (39) | <0.001 | 42 (65) | 40 (62) | 0.856 |
| Regurgitation | 1 (1) | 59 (31) | <0.001 | 1 (2) | 1 (2) | 1.000 |
| Stenosis and regurgitation | 25 (27) | 54 (28) | 0.916 | 22 (34) | 23 (35) | 1.000 |
| Infective endocarditis | 1 (1) | 16 (8) | 0.030 | 1 (2) | 6 (9) | 0.120 |
| Bicuspid aortic valve (%) | 10 (11) | 64 (33) | <0.001 | 10 (15) | 7 (11) | 0.603 |
| Sievers type | 0.230 | 0.732 | ||||
| Type 0 | 1 (10) | 23 (36) | 1 (10) | 2 (29) | ||
| Type 1 | 9 (90) | 40 (63) | 9 (90) | 5 (71) | ||
| Type 2 | 0 | 1 (2) | 0 | 0 | ||
| Cardiac comorbidity (%) | ||||||
| Atrial fibrillation | 25 (27) | 40 (21) | 0.335 | 17 (26) | 13 (22) | 0.532 |
| First-degree AVB | 2 (2) | 3 (2) | 1.000 | 2 (3) | 1 (2) | 0.989 |
| Second degree AVB | 0 | 0 | NaN | 0 | 0 | NaN |
| Third-degree AVB | 2 (2) | 2 (1) | 0.830 | 1 (2) | 2 (3) | 1.000 |
| CLBBB | 3 (3) | 4 (2) | 0.855 | 3 (5) | 1 (2) | 0.600 |
| IRBBB | 3 (3) | 4 (2) | 0.855 | 1 (2) | 1 (2) | 1.000 |
| CRBBB | 9 (10) | 19 (10) | 1.000 | 7 (11) | 9 (14) | 0.789 |
| History of AMI | 6 (6) | 12 (6) | 1.000 | 4 (6) | 6 (9) | 0.742 |
| History of PCI | 6 (6) | 17 (9) | 0.632 | 2 (3) | 8 (12) | 0.100 |
| Previous cardiac surgery | 12 (13) | 22 (11) | 0.887 | 7 (11) | 10 (15) | 0.603 |
| Non-cardiac comorbidity | ||||||
| Hypertension (%) | 64 (68) | 117 (61) | 0.272 | 43 (66) | 42 (65) | 1.000 |
| Dyslipidemia (%) | 50 (53) | 86 (45) | 0.212 | 33 (51) | 34 (52) | 1.000 |
| Diabetes (%) | 17 (18) | 22 (11) | 0.171 | 12 (19) | 13 (20) | 1.000 |
| Diabetes with insulin (%) | 5 (5) | 6 (3) | 0.557 | 4 (6) | 4 (6) | 1.000 |
| Chronic kidney disease (%) | 64 (68) | 90 (47) | 0.001 | 41 (63) | 30 (46) | 0.078 |
| Dialysis (%) | 15 (16) | 5 (3) | <0.001 | 6 (9) | 4 (6) | 0.742 |
| History of stroke (%) | 8 (9) | 22 (11) | 0.586 | 4 (6) | 7 (11) | 0.529 |
| Peripheral vascular disease (%) | 4 (4) | 6 (3) | 0.877 | 1 (2) | 4 (6) | 0.362 |
| B-type natriuretic peptide (pg/mL) | 456±901 | 296±614 | 0.079 | 348±631 | 379±950 | 0.828 |
| NYHA classification (%) | 0.453 | 0.452 | ||||
| I | 16 (17) | 45 (23) | 12 (19) | 7 (11) | ||
| II | 63 (67) | 122 (63) | 44 (68) | 44 (68) | ||
| III | 12 (13) | 17 (9) | 7 (11) | 12 (19) | ||
| IV | 3 (3) | 9 (5) | 2 (3) | 2 (3) | ||
| STS risk score (%) | 5.5±6.4 | 3.7±4.4 | 0.005 | 5.0±6.1 | 5.1±5.2 | 0.933 |
| Preoperative echocardiography | ||||||
| LVEDD (mm) | 48±7 | 54±11 | <0.001 | 48±8 | 49±8 | 0.726 |
| LVESD (mm) | 32±7 | 38±12 | <0.001 | 32±8 | 32±8 | 0.722 |
| LVEF (%) | 61±10 | 56±13 | 0.003 | 61±11 | 61±10 | 0.900 |
| LVMI (g/m2) | 116±35 | 127±42 | 0.036 | 116±35 | 115±31 | 0.786 |
| EOA (cm2) | 0.84±0.26 | 1.02±0.67 | 0.016 | 0.87±0.28 | 0.92±0.40 | 0.401 |
| EOAI (cm2/m2) | 0.56±0.21 | 0.63±0.41 | 0.127 | 0.58±0.23 | 0.59±0.29 | 0.776 |
| MPG (mmHg) | 46±18 | 46±23 | 0.908 | 44±20 | 46±22 | 0.587 |
| Peak velocity (m/s) | 4.3±0.9 | 4.0±1.3 | 0.049 | 4.2±0.9 | 4.1±1.1 | 0.769 |
| Aortic valve annulus (mm) | 20.8±2.3 | 22.7±3.2 | <0.001 | 21.0±2.5 | 21.5±2.7 | 0.246 |
| Sinotubular junction (mm) | 25.5±3.8 | 29.1±6.1 | <0.001 | 26.1±3.8 | 26.2±4.8 | 0.911 |
| Valsalva sinus (mm) | 31.8±4.8 | 35.8±6.5 | <0.001 | 31.5±3.6 | 32.4±4.8 | 0.199 |
Data are presented as mean±standard deviation or n (%). AMI, acute myocardial infarction; AVB, atrioventricular block; CLBBB, complete left bundle branch block; CRBBB, complete right bundle branch block; EOA, effective orifice area; EOAI, effective orifice area index; IRBBB, incomplete right bundle branch block; LVEDD, left ventricular end-diastolic dimension; LVEF, left ventricular ejection fraction; LVESD, left ventricular end-systolic dimension; LVMI, left ventricular mass index; MPG, mean pressure gradient; NaN, not a number; NYHA, New York Heart Association; PCI, percutaneous coronary intervention; STS, Society of Thoracic Surgery.
The operative details are shown in Table 2. In the unmatched cohort, minimally invasive cardiac surgery was similarly performed in the 2 groups (Intuity: n=10, 11%; conventional: n=28, 15%; P=0.470). Concomitant procedures for coronary artery bypass grafting and tricuspid annuloplasty were more frequent, and aortic surgery was less frequent in the Intuity group than in the conventional group. The implanted prosthetic valve size was significantly smaller in the Intuity group than in the conventional group (P<0.001). The most frequently implanted valve size was 19 mm (n=31, 33%) in the Intuity group, and 21 mm and 23 mm (n=57, 30%) in the conventional group (Figure 1).
| Unmatched cohort | Matched cohort | |||||
|---|---|---|---|---|---|---|
| Intuity (n=94) |
Conventional (n=193) |
P value | Intuity (n=65) |
Conventional (n=65) |
P value | |
| Operative results | ||||||
| MICS procedure (%) | 10 (11) | 28 (15) | 0.470 | 8 (12) | 5 (8) | 0.559 |
| Isolated AVR (%) | 34 (36) | 81 (42) | 0.417 | 26 (40) | 27 (42) | 1.000 |
| Concomitant Procedure | 0.197 | 0.378 | ||||
| CABG (%) | 32 (34) | 29 (15) | <0.001 | 16 (25) | 17 (26) | 1.000 |
| Maze (%) | 16 (17) | 22 (11) | 0.257 | 12 (19) | 5 (8) | 0.119 |
| Mitral valve surgery (%) | 21 (22) | 35 (18) | 0.493 | 17 (26) | 15 (23) | 0.839 |
| Tricuspid annuloplasty (%) | 17 (18) | 13 (7) | 0.006 | 12 (19) | 5 (8) | 0.119 |
| Surgery for thoracic aorta (%) | 3 (3) | 28 (15) | 0.007 | 3 (5) | 5 (8) | 0.715 |
| Operation time (min) | 271±79 | 311±125 | 0.004 | 260±74 | 338±165 | 0.001 |
| Cardiopulmonary bypass time (min) | 138±49 | 166±69 | <0.001 | 135±46 | 172±75 | 0.001 |
| Aortic cross-clamping time (min) | 95±38 | 119±48 | <0.001 | 92±34 | 123±53 | <0.001 |
| Blood transfusion (%) | 89 (95) | 169 (88) | 0.095 | 60 (92) | 64 (99) | 0.210 |
| Postoperative results | ||||||
| Ventilation time (h) | 21.5±49 | 23.5±59.1 | 0.775 | 11.8±9.1 | 27.4±45.4 | 0.008 |
| Intensive care unit stay (days) | 4±3 | 4±7 | 0.430 | 3±2 | 5±7 | 0.041 |
| Hospital stay (days) | 17±15 | 19±16 | 0.421 | 17±17 | 18±11 | 0.795 |
| In-hospital complications | ||||||
| Mortality (%) | 2 (2) | 1 (1) | 0.535 | 2 (3) | 0 | 0.490 |
| Atrial fibrillation (%) | 45 (48) | 84 (44) | 0.570 | 31 (48) | 31 (48) | 1.000 |
| Pacemaker for CAVB (%) | 3 (3) | 2 (1) | 0.407 | 2 (3) | 0 | 0.476 |
| CLBBB | 14 (15) | 4 (2) | <0.001 | 12 (19) | 2 (3) | 0.011 |
| Disabling stroke (%) | 1 (1) | 1 (1) | 1.000 | 0 | 0 | NaN |
| 1-year complications | ||||||
| Survival rate (%) | 96 | 97 | 1.000 | 97 | 96 | 1.000 |
| Freedom rate from MACCEs (%) | 96 | 97 | 1.000 | 97 | 96 | 1.000 |
| Stroke (%) | 1 (1) | 0 | 0.759 | 1 (2) | 0 | 1.000 |
| Pacemaker for CAVB (%) | 0 | 2 (2) | 0.758 | 0 | 1 (2) | 0.927 |
| Reoperation (%) | 1 (1) | 1 (1) | 1.000 | 1 (2) | 1 (2) | 1.000 |
| Follow-up period (months) | 14.8±8.7 | 14.2±8.1 | 0.561 | 17.5±8.3 | 14.3±8.7 | 0.033 |
Data are presented as mean±standard deviation or n (%). AVR, aortic valve replacement; CABG, coronary artery bypass grafting; CAVB, complete atrioventricular block; MACCEs, major adverse cardiac and cerebrovascular events; MICS, minimally invasive cardiac surgery. Other abbreviations as in Table 1.
Distribution of valve size used in the unmatched cohort. Data are presented as n (%).
In the matched cohort, the frequency of concomitant procedures was similar between the 2 groups. Operation-related times including operation time, cardiopulmonary bypass time, and aortic cross-clamping time were significantly shorter in the Intuity group (operation time, 260±74 min; cardiopulmonary bypass time, 135±46 min; aortic cross-clamping time, 92±34 min) than in the conventional group (operation time, 338±165 min, P=0.001; cardiopulmonary bypass time, 172±75 min, P=0.001; aortic cross-clamping time, 123±53 min, P<0.001). The size of the implanted prosthetic valve was comparable between the 2 groups (Figure 2, P=0.173). Regarding isolated primary AVR, these 3 operation-related times were also significantly shorter in the Intuity group than in the conventional group in both the unmatched and matched cohorts (Supplementary Table).
Distribution of valve size in the matched cohort. Data are presented as n (%).
The in-hospital and 1-year postoperative results are also detailed in Table 2. In the unmatched cohort, in-hospital death occurred in 2 cases (2%) in the Intuity group due to acute chronic kidney disease and sepsis and in 1 patient (1%) in the conventional group due to pneumonia. Disabling stroke developed in 1 patient in each group. Pacemaker implantation due to complete atrioventricular block occurred in 3 patients in the Intuity group (3%) and 2 patients in the conventional group (1%), with no significant difference (P=0.407). Complete left bundle branch block developed more frequently in the Intuity group (n=14, 15%) than in the conventional group (n=4, 2%, P<0.001). In the matched cohort, the ventilation time and intensive care unit stay were significantly shorter in the Intuity group than in the conventional group. Moreover, the incidence of complete atrioventricular block was comparable, and no disabling stroke developed in either group. The development of complete left bundle branch block was significantly higher in the Intuity group (n=12, 19%) than in the conventional group (n=2, 3%, P=0.011). At 1-year postoperatively in the unmatched cohort, the survival rates in the Intuity and conventional groups were 96% and 97%, respectively, and freedom from MACCEs was 96% and 97%, respectively. In the matched cohort, the survival rates in the Intuity and conventional groups were 97% and 96%, respectively, and freedom from MACCEs was 97% and 96%, respectively. In the Intuity group, 1 patient, who had a postoperative moderate PVL, underwent reoperation due to heart failure and was diagnosed with hemolytic anemia 8 months after the initial operation. In the conventional group, 1 patient required reoperation due to prosthetic valve endocarditis, 9 months after the initial AVR.
Valve Performance at 1-Week and 1-Year Postoperatively in the Unmatched CohortThe postoperative valve performance in the unmatched cohort is detailed in Table 3. At 1-week postoperatively, the echocardiography showed comparable valve performance between the Intuity group and the conventional group (EOAI: 1.00±0.26 cm2/m2 vs. 1.03±0.29 cm2/m2, P=0.448; a transvalvular MPG: 12.7±5.2 mmHg vs. 12.4±4.7 mmHg, P=0.634; transvalvular peak velocity: 2.4±0.5 m/s vs. 2.4±0.4 m/s, P=0.569). One-year postoperatively, EOAI and transvalvular peak velocity were comparable between the 2 groups (EOAI: 0.98±0.21 cm2/m2 vs. 0.98±0.31 cm2/m2, P=0.859; transvalvular peak velocity: 2.3±0.5 m/s vs. 2.4±0.5 m/s, P=0.224). The transvalvular MPG was significantly smaller in Intuity group (11.6±4.7 mmHg) than in the conventional group (13.3±5.2 mmHg, P=0.030). When assessing the valve performance over time, the Intuity group showed a steady valve performance; EOAI or peak velocity did not significantly change over time, and MPG decreased significantly (P=0.029, Figure 3). However, the conventional group showed a significantly deteriorated valve performance between 1-week and 1-year postoperatively; EOAI decreased (P=0.009) and MPG and peak velocity increased (P=0.029, P=0.049). The 3 most used valves, Avalus, Inspiris, and Intuity, were compared according to size and are summarized in the Supplementary Figure. At 21 mm, the Intuity valve showed a better MPG and peak velocity compared to Avalus and Inspiris at 1 year after surgery.
| 1 week | 1 year | |||||
|---|---|---|---|---|---|---|
| Intuity (n=93) |
Conventional (n=193) |
P value | Intuity (n=61) |
Conventional (n=127) |
P value | |
| EOA (cm2) | 1.53±0.37 | 1.65±0.51 | 0.048 | 1.53±0.37 | 1.56±0.45 | 0.642 |
| EOAI (cm2/m2) | 1.00±0.26 | 1.03±0.29 | 0.448 | 0.98±0.21 | 0.98±0.31 | 0.859 |
| MPG (mmHg) | 12.7±5.2 | 12.4±4.7 | 0.634 | 11.6±4.7 | 13.3±5.2 | 0.030 |
| Peak velocity (m/s) | 2.4±0.5 | 2.4±0.4 | 0.569 | 2.3±0.5 | 2.4±0.5 | 0.224 |
| Paravalvular leak (%) | 0.012 | 0.732 | ||||
| ≤Trivial | 81 (87) | 187 (97) | 0.003 | 53 (87) | 116 (91) | 0.490 |
| Mild | 11 (12) | 6 (3) | 0.008 | 7 (12) | 10 (8) | 0.593 |
| Moderate | 1 (1) | 0 | 0.709 | 1 (2) | 1 (1) | 1.000 |
| Severe PPM (%) | 5 (6) | 4 (2) | 0.289 | 3 (5) | 8 (7) | 0.890 |
Data are presented as mean±standard deviation or n (%). PPM, prosthesis-patient mismatch. Other abbreviations as in Table 1.
Trend in effective orifice area index (A), mean pressure gradient (B), peak velocity (C), and left ventricular mass index (D) for the unmatched cohort. The comparison between the conventional and the Intuity groups at each time point and the changes over time at 1-month and 1-year postoperatively for each group (Intuity group: red; conventional group: blue) are shown. EOAI, effective orifice area index; LVMI, left ventricular mass index; MPG, mean pressure gradient.
The postoperative valve performance in the matched cohort is detailed in Table 4. In the unmatched cohort, EOAI, MPG, and peak velocity were similar between the 2 groups at 1-week postoperatively. At 1-year postoperatively, MPG and peak velocity were significantly lower in the Intuity group (P=0.006, P=0.017). Regarding the changes in valve performance over time, both groups showed no significant change between 1-week and 1-year postoperatively, except that EOAI in the conventional group decreased (P=0.014), and MPG in the Intuity group improved significantly (P=0.010, Figure 4).
| 1 week | 1 year | |||||
|---|---|---|---|---|---|---|
| Intuity (n=64) |
Conventional (n=65) |
P value | Intuity (n=51) |
Conventional (n=42) |
P value | |
| EOA (cm2) | 1.51±0.36 | 1.60±0.46 | 0.224 | 1.54±0.38 | 1.47±0.32 | 0.327 |
| EOAI (cm2/m2) | 0.99±0.28 | 1.02±0.27 | 0.600 | 0.98±0.21 | 0.96±0.23 | 0.723 |
| MPG (mmHg) | 12.9±5.8 | 13.7±5.6 | 0.461 | 11.4±4.6 | 14.5±6.0 | 0.006 |
| Peak velocity (m/s) | 2.4±0.5 | 2.5±0.5 | 0.407 | 2.3±0.5 | 2.6±0.5 | 0.017 |
| Paravalvular leak (%) | 0.242 | 0.679 | ||||
| ≤Trivial | 56 (88) | 63 (97) | 0.095 | 45 (88) | 39 (93) | 0.691 |
| Mild | 7 (11) | 2 (3) | 0.160 | 5 (10) | 3 (7) | 0.933 |
| Moderate | 1 (2) | 0 | 0.994 | 1 (2) | 0 | 1.000 |
| Severe PPM (%) | 5 (9) | 0 | 0.095 | 2 (4) | 1 (3) | 1.000 |
Data are presented as mean±standard deviation or n (%). Abbreviations as in Tables 1,3.
Trend in effective orifice area index (A), mean pressure gradient (B), peak velocity (C), and left ventricular mass index (D) for the matched cohort. The comparison between the conventional and the Intuity groups at each time point and the changes over time at 1-month and 1-year postoperatively for each group are shown (Intuity group: red; conventional group: blue). EOAI, effective orifice area index; LVMI, left ventricular mass index; MPG, mean pressure gradient.
In the unmatched cohort, severe PPM was observed in 6% of the Intuity group at 1 week, postoperatively, and the incidence did not differ between the 2 groups at both 1 week and 1 year, postoperatively (Table 3). Mild or greater PVL was prevalent in the Intuity group at 1 week postoperatively (P=0.003), but there was no significant difference at 1 year postoperatively (P=0.490). LVMI was comparable between the 2 groups at 1 year postoperatively and regressed significantly compared with the preoperative value (Figure 3D). In the matched cohort, there was no difference in the incidence of severe PPM between the 2 groups at 1 week or 1 year postoperatively. Although mild or greater PVL was observed in 13% of patients at 1-week and 12% of patients at 1-year postoperatively in the Intuity group, no significant differences were observed between the 2 groups at each point (Table 4). LVMI did not differ between the 2 groups at 1-year postoperatively. Both groups showed significant LVMI regression compared to preoperative values (Figure 4D).
We compared the early outcomes of patients who underwent surgical AVR with Intuity or conventional valves using propensity score matching. After matching, the Intuity group had a mortality rate of 3% and a permanent pacemaker implantation rate of 3%, which were comparable to those of the conventional group. Although the incidence of PVL was also comparable between the 2 groups, mild or greater PVL was observed in 13% of the Intuity group. The incidence of severe PPM did not differ between the 2 groups at 1-week or 1-year postoperatively. Operation, cardiopulmonary bypass, and aortic cross-clamping times were significantly shorter in the Intuity group than in the conventional group. In patients who underwent isolated primary AVR using the Intuity valve, the aortic cross-clamping time was reduced by two-thirds compared with when conventional valves were used.
For the valve performance in the matched cohort, EOAI was similar between the 2 groups at 1-week and 1-year postoperatively, but trans-prosthetic MPG and peak velocity were significantly lower in the Intuity group than in the conventional group at 1-year postoperatively. As suggested in previous studies, AVR without pledgets may be related to a low-pressure gradient through the prosthesis.17,18 Intuity has a skirt stent frame that widens the left ventricular outflow tract, which may help to decrease the pressure gradient during reverse remodeling by decreasing the turbulence of blood flow.19–21 Although numerous bioprostheses increase the pressure gradient gradually over time, the 1-year outcome of the Intuity valve, with this unique feature, is long-term durability.22,23
A previous meta-analysis showed that the pacemaker implantation rate after AVR, using Intuity, ranged from 3% to 12%.24 Right bundle branch block and larger prosthesis sizes are reported to increase the pacemaker rate after Intuity implantation, and high balloon pressure is a risk factor for permanent pacemaker implantation in sutureless valves.6,25,26 Vogt et al also reported that appropriate decalcification and guiding sutures are the key to avoiding postoperative pacemakers.26 The pacemaker implantation rate in our cohort was as low as 3%; however, left bundle branch block occurred in 15% of patients. Therefore, Intuity implantation has a potential risk for complete atrioventricular block, especially in patients with right bundle branch block.
In a breakthrough transcatheter AVR study, moderate or severe PVL was a risk factor for long-term mortality, but mild PVL was not responsible for mortality, and neither was no or a trace of PVL.27 Although mild or greater PVL was present in 13% of the Intuity group 1-week postoperatively, moderate PVL occurred in 1% of the group and none had severe PVL. In addition, the significant difference in the prevalence of PVL between the 2 groups disappeared 1-year postoperatively. Our study cohort showed a relatively low incidence of complete atrioventricular block, and it appeared to be a trade-off for the high incidence of mild PVL. In other words, the selection of a relatively small prosthesis in the Intuity group may be related to the low atrioventricular block rate and the high PVL rate. Given the low-pressure gradient with the 19-mm valve in the Intuity group (13.8 mmHg at 1 week and 13.4 mmHg at 1 year), this selection of the valve size and mild PVL 1-week postoperatively would be acceptable.
The use of an Intuity valve in other studies resulted in reduced operation-related times because of the simplified technique used.5,28 The operation-related time was also reduced in the present study. Longer cross-clamping times are reported to be a risk factor for postoperative mortality;29 therefore, the Intuity valve would contribute to the improved outcomes for patients undergoing AVR in this aspect. The Intuity valve was predominantly selected for patients who had a potential risk but did not appear in the risk score because of features that can shorten the cross-clamping time. Therefore, there are patients who would benefit from the use of the Intuity valve.
Study LimitationsThe present study had limitations. First, this was a single-center, retrospective study. Although there is homogeneity in perioperative management, the limited number of patients may have resulted in an insufficient statistical power. Second, even though propensity score marching was conducted to correct for the patients’ characteristics between the 2 groups, each patient’s background might not have been consistent across the groups. Finally, the lack of medication use data and other potential unmeasured confounders might have affected the results.
AVR using the Intuity valve in Japanese patients is satisfactory, with improved valve performance at 1-year postoperatively. Selection of appropriate candidates and the correct sizes of prostheses are keys to take advantage of the Intuity valve performance. Further follow-up evaluations are required to elucidate the long-term mortality and valve durability.
The authors declare that they have no conflicts of interest.
The National Cerebral and Cardiovascular Center Institutional Review Board (M30-026-4) approved this study.
Please find supplementary file(s);
http://dx.doi.org/10.1253/circj.CJ-21-0959
