Long-Term Outcomes After Aortic Valve Replacement for Aortic Valve Regurgitation　― Importance of Left Ventricular End-Systolic Diameter ―

Abstract

Background: We determined the left ventricular end-systolic diameter (LVDs) cut-off value for risk of major adverse cardiac and cerebrovascular events (MACCE) in Japanese asymptomatic or mildly symptomatic patients undergoing aortic valve replacement (AVR) for aortic valve regurgitation (AR), and investigated the effect of left ventricular dilation on long-term postoperative outcomes.

Methods and Results: The 168 patients who underwent surgical AVR for AR at Shiga University of Medical Science between January 2002 and December 2022 were included in this study. Receiver operating characteristic curve analysis showed that the cut-off value of preoperative LVDs for the incidence of MACCE was 42.8 mm (area under the curve 0.616). Postoperative outcomes were compared between patients with preoperative LVDs >42.8 mm (n=77) and those with preoperative LVDs ≤42.8 mm (n=91) using propensity score matching. The 10-year estimated rates of freedom from MACCE in those with LVDs >42.8 and ≤42.8 mm were 59.9% and 85.7%, respectively; the curves differed significantly (P=0.004). In multivariable Cox proportional hazard regression analyses, preoperative LVDs >42.8 mm was an independent predictor of MACCE (hazard ratio 2.485; 95% confidence interval 1.239–4.984; P=0.010).

Conclusions: Preoperative LVDs >42.8 mm is associated with an increased risk of MACCE in Japanese patients undergoing AVR for AR.

Aortic valve regurgitation (AR) induces volume overload in the left ventricle (LV) and leads to increased wall stress and LV mass (LVM). In addition, reduced diastolic blood pressure caused by AR impairs coronary blood flow and causes global ischemia of the LV tissue. As a result, in patients with severe AR, pathological hypertrophy of LV myocytes and subsequent deterioration of the contractile function of the LV, including dilation of the LV cavity, occur.^1–3

Editorial p 1962

The American College of Cardiology (ACC)/American Heart Association (AHA) guidelines recommend aortic valve replacement (AVR) for asymptomatic patients with LV end-systolic diameter (LVDs) >50 mm (Class IIa indication).⁴ Guidelines from the European Society of Cardiology (ESC)/European Association for Cardio-Thoracic Surgery (EACTS) also recommend AVR for asymptomatic patients with LVDs >50 mm (Class I indication).⁵ Conversely, guidelines from the Japanese Circulation Society (JCS)/Japanese Society for Cardiovascular Surgery (JSCS)/Japanese Association for Thoracic Surgery (JATS)/Japanese Society for Vascular Surgery (JSVS) recommend AVR for asymptomatic patients with LVDs >45 mm (Class IIa indication).⁶ This difference is due to the physical difference between Western and Japanese populations, but there is only one report on the cut-off value of LVDs for the Japanese population.⁷ The purpose of the present study was to determine the LVDs cut-off value for major adverse cardiac and cerebrovascular events (MACCE) in Japanese asymptomatic or mildly symptomatic patients undergoing AVR for AR, and to investigate the effect of LV dilation on long-term postoperative outcomes.

Methods

All patients had previously granted permission for the use of their medical records for research purposes. This study was approved by the Institutional Review Board of Shiga University of Medical Science (Reference no. R2023-090; approval date November 2, 2023). The procedures in this study were conducted in accordance with the Declaration of Helsinki.

Between January 2002 and December 2022, 1,580 patients underwent surgical AVR at Shiga University of Medical Science. Of these patients, 485 underwent AVR for the treatment of AR. We excluded 260 patients who underwent concomitant coronary artery bypass surgery or concomitant surgery on other valves, who had infective endocarditis prior to the surgery, or who underwent AVR for moderate AR at the time of thoracic aortic surgery. We excluded a further 57 patients with preoperative New York Heart Association (NYHA) functional class III or greater. Thus, 168 patients were finally included in the study. We retrospectively evaluated survival and echographic data for these patients during the follow-up period. As subgroup analyses, in addition to preoperative LVDs, we examined the effects of preoperative LV ejection fraction (LVEF) and the LVDs index (LVDsI) on long-term outcomes.

Surgical Treatment

In our cohort, all patients underwent median sternotomy. Myocardial protection was obtained for all patients by means of an antegrade or retrograde infusion using a cold blood cardioplegia solution. Valves, selected according to each surgeon’s preference, were implanted in the supra- or intra-annular position, also in accordance with each surgeon’s preference. After completion of AVR, the aortotomy was sutured using 4-0 monofilament continuous sutures in 2 layers, or by using 4-0 monofilament horizontal mattress sutures and continuous sutures.

Echocardiographic Measurements

Patients underwent annual echocardiographic follow-up at Shiga University of Medical Science. The LV dimensions were assessed using 2-dimensional ultrasound-guided M-mode tracings. Measurements of the LV end-diastolic diameter (LVDd), interventricular septal thickness at end diastole (IVSD), and posterior wall thickness at end diastole (PWD; all in millimeters), were used to calculate LVM using the formula of Devereux et al,⁸ as follows:

LVM = 0.8 (1.04 [{LVDd + IVSD + PWD}³ – LVDd³]) + 0.6

An LVM index (LVMI) was calculated by dividing LVM by body surface area (BSA). Similarly, an LVDsI was calculated by dividing LVDs by BSA. LVEF was calculated using the Simpson method.

Outcome Measures and Definitions

The primary outcome was the incidence of MACCE, defined as a composite of all-cause mortality, non-fatal myocardial infarction (MI), non-fatal heart failure including additional cardiac operations, non-fatal stroke, and repeat revascularization. Non-fatal MI, non-fatal heart failure, and non-fatal stroke were defined as new admissions with a diagnosis of these diseases during the follow-up period that did not result in death.

Statistical Analysis

Continuous variables are presented as the mean±SD and categorical variables are presented as percentages. Continuous variables were compared between patient groups using t-tests or Mann-Whitney U tests. Categorical variables were analyzed using Pearson’s χ² test. Probabilities of survival were estimated using the Kaplan-Meier method, for which patient survival time was measured from the date of surgery until death or the final date of follow-up; the long-rank test was used to compare groups. Univariable and multivariable Cox proportional hazards regression analyses were performed to analyze predictors of all-cause mortality and MACCE. Variables reaching P<0.100 in the univariable analysis and those that were considered clinically important were entered into the multivariable model. All statistical testing was 2-sided and results were considered statistically significant at P<0.050.

The area under curve (AUC) was calculated by obtaining the receiver operating characteristic (ROC) curve from the logistic regression model for the incidence of MACCE. The cut-off value with the most favorable sensitivities and specificities was determined using the Youden index from the ROC curve.

Propensity score matching was used to account for non-equivalence of baseline characteristics between patients with greater (>42.8 mm) and smaller (≤42.8 mm) LVDs. A multivariable logistic regression model was used to create the propensity score based on the following 15 adjustment variables to derive the propensity score: age, sex, body mass index, hypertension, diabetes, dyslipidemia, smoking history, history of percutaneous coronary intervention, previous cerebrovascular accident, estimated glomerular filtration rate <60 ml/min/1.73 m², preoperative hemodialysis, redo surgery, bicuspid aortic valve, NYHA Class II.

All statistical analyses were performed using SPSS version 25.0 (IBM Corp., Armonk, NY, USA) and SAS version 9.4 (SAS Institute, Cary, NC, USA).

Results

ROC analysis showed that the preoperative LVDs cut-off value for the incidence of MACCE was 42.8 mm (AUC: 0.616; Supplementary Figure 1). In this study, 77 patients had preoperative LVDs >42.8 mm and 91 patients had preoperative LVDs of ≤42.8 mm.

Preoperative participant characteristics are summarized in Table 1. In the unmatched cohort, the proportion of men was greater in the group with LVDs >42.8 than ≤42.8 mm (85.7% vs. 60.4%, respectively; P<0.001) and BSA was significantly greater in the group with LVDs >42.8 mm (1.70 vs. 1.59 m²; P=0.001). Propensity score matching resulted in 62 successful 1 : 1 pairs. The model was well calibrated (Hosmer-Lemeshow test, P=0.687), with reasonable discrimination (C-statistic 0.657). In the matched cohort, the 2 groups were well balanced in their baseline characteristics.

Table 1.

Preoperative Patient Characteristics

	Unmatched cohort			Matched cohort
	LVDs >42.8 mm (n=77)	LVDs ≤42.8 mm (n=91)	P value	LVDs >42.8 mm (n=62)	LVDs ≤42.8 mm (n=62)	P value
Age (years)	63.2±14.0	64.7±11.9	0.453	63.6±14.5	62.7±11.8	0.694
Male sex	66 (85.7)	55 (60.4)	<0.001	52 (83.9)	53 (85.5)	0.805
Body mass index (kg/m2)	22.9±3.5	22.0±3.4	0.097	22.5±3.3	22.4±3.3	0.884
Body surface area (m2)	1.70±0.19	1.59±0.22	0.001	1.69±0.18	1.67±0.19	0.534
Hypertension	46 (59.7)	51 (56.0)	0.631	37 (59.7)	33 (53.2)	0.473
Diabetes	9 (11.7)	7 (7.7)	0.382	5 (8.1)	7 (11.3)	0.547
Dyslipidemia	16 (20.8)	19 (20.9)	0.987	13 (21.0)	11 (17.7)	0.653
Smoking history	43 (55.8)	41 (45.1)	0.165	37 (59.7)	36 (58.1)	0.857
Previous PCI	2 (2.6)	2 (2.2)	0.867	2 (3.2)	1 (1.6)	0.563
Previous CVD	7 (9.1)	6 (6.6)	0.549	6 (9.7)	4 (6.5)	0.513
eGFR <60 mL/min/1.73 m2	28 (36.4)	32 (35.2)	0.873	25 (40.3)	20 (32.3)	0.354
Hemodialysis	2 (2.6)	2 (2.2)	0.867	2 (3.2)	1 (1.6)	0.563
Redo surgery	5 (6.5)	8 (8.8)	0.581	5 (8.1)	5 (8.1)	1.000
Emergency operation	0 (0)	0 (0)	–	0 (0)	0 (0)	–
Bicuspid aortic valve	18 (23.4)	16 (17.6)	0.355	12 (19.4)	14 (22.6)	0.662
Annuloaortic ectasia	4 (5.2)	3 (3.3)	0.542	3 (4.8)	3 (4.8)	1.000
NYHA functional class			0.776			0.850
II	50 (64.9)	61 (67.0)		42 (67.7)	41 (66.1)
I	27 (35.1)	30 (33.0)		20 (32.3)	21 (33.9)
Echographic data
LVEF (%)	51.1±8.8	60.8±7.8	<0.001	51.1±8.8	61.0±7.5	<0.001
LVDd (mm)	67.2±5.4	56.1±5.5	<0.001	67.0±5.6	57.4±4.9	<0.001
LVDs (mm)	48.8±4.9	37.2±3.7	<0.001	48.8±4.9	38.0±3.3	<0.001
LVMI (g/m2)	217±47	161±37	<0.001	221±48	163±36	<0.001

Unless indicated otherwise, data are given as the mean±SD or n (%). CVD, cerebrovascular disease; eGFR, estimated glomerular filtration rate; LVDd, left ventricular end-diastolic diameter; LVDs, left ventricular end-systolic diameter; LVEF, left ventricular ejection fraction; LVMI, left ventricular mass index; NYHA, New York Heart Association; PCI, percutaneous coronary intervention.

Before and after propensity score matching, LVDd, LVDs, and LVMI were larger in the group with LVDs >42.8 than in the group with LVDs ≤42.8 mm. LVEF was smaller in the group with LVDs >42.8 than in the group with LVDs ≤42.8 mm.

Early Outcomes

Operative and postoperative outcomes are presented in Table 2. Before and after propensity score matching, implanted valve size was significantly larger in the group with LVDs >42.8 mm than in the group with LVDs ≤42.8 mm. Postoperative echography showed that in the unmatched cohort there was 1 (1.3%) patient in the group with LVDs >42.8 mm with a postoperative effective orifice area index <0.85 cm²/m². In the matched cohort, there was 1 (1.6%) patient in the group with LVDs >42.8 mm with this. In our entire cohort, no patients had structural valve deterioration (SVD), thrombosis, or abnormal pannus formation.

Table 2.

Operative and Postoperative Data

	Unmatched cohort			Matched cohort
	LVDs >42.8 mm (n=77)	LVDs ≤42.8 mm (n=91)	P value	LVDs >42.8 mm (n=62)	LVDs ≤42.8 mm (n=62)	P value
Operative data
Operation time (min)	197±47	192±55	0.540	194±50	194±49	0.958
Cardiopulmonary bypass time (min)	97±25	95±33	0.728	96±25	96±32	0.985
Aortic clamp time (min)	63±19	62±24	0.755	64±19	62±25	0.716
Bioprosthetic valve	52 (67.5)	62 (68.1)	0.934	44 (71.0)	37 (59.7)	0.190
Valve size (mm)	25.7±1.5	24.3±2.1	<0.001	25.6±1.6	24.9±2.0	0.031
Concomitant procedures
Bentall	9 (11.7)	7 (7.7)	0.382	7 (11.3)	5 (8.1)	0.547
Hemiarch	4 (5.2)	6 (6.6)	0.705	3 (4.8)	3 (4.8)	1.000
Total arch replacement	1 (1.3)	3 (3.3)	0.400	1 (1.6)	2 (3.2)	0.563
Maze	4 (5.2)	8 (8.8)	0.370	3 (4.8)	6 (9.7)	0.303
Postoperative data
ICU stay >48 h	4 (5.2)	1 (1.1)	0.143	3 (4.8)	0 (0)	0.083
Ventilation >48 h	3 (3.9)	3 (3.3)	0.836	2 (3.2)	1 (1.6)	0.563
30-day mortality	0 (0)	0 (0)	–	0 (0)	0 (0)	–
Hospital mortality	0 (0)	0 (0)	–	0 (0)	0 (0)	–
Echographic data
Effective orifice area index (cm2/m2)	1.21±0.24	1.31±0.22	0.007	1.20±0.23	1.30±0.23	0.014
LVEF (%)	46.1±9.0	55.0±7.6	<0.001	45.5±9.3	54.7±7.4	<0.001
LVDd (mm)	58.1±6.4	48.9±5.9	<0.001	58.0±6.4	50.3±6.0	<0.001
LVDs (mm)	44.8±6.6	34.9±5.9	<0.001	45.0±6.9	35.6±6.4	<0.001
LVMI (g/m2)	175±43	136±39	<0.001	181±43	141±41	<0.001

Unless indicated otherwise, data are given as the mean±SD or n (%). ICU, intensive care unit. Other abbreviations as in Table 1.

Long-Term Outcomes

Follow-up was completed for 99.4% (167/168) of study participants, and the mean follow-up duration was 7.4±5.2 years (maximum 20.8 years). Causes of MACCE are presented in Table 3. In the unmatched cohort, the 10-year estimated rates of freedom from MACCE in the group with LVDs >42.8 mm compared with the group with LVDs ≤42.8 mm were 69.7% and 84.8%, respectively (Figure 1); the curves differed significantly (P=0.010). In the matched cohort, the 10-year estimated rates of freedom from MACCE in the LVDs >42.8 mm and LVDs ≤42.8 mm groups were 59.9% and 85.7%, respectively (Figure 2); again, the curves differed significantly (P=0.004). In the entire cohort, during follow-up, 4 patients underwent surgical AVR for AR associated with SVD, 1 patient underwent transcatheter AVR for AR associated with SVD, and 1 patient underwent a Bentall procedure for prosthetic valve endocarditis in the group with LVDs >42.8 mm. In the group with LVDs ≤42.8 mm, 2 patients underwent surgical AVR for AR associated with SVD, 1 patient underwent surgical AVR for aortic stenosis associated with SVD, and 1 patient underwent mitral valve plasty for mitral regurgitation.

Table 3.

Causes of MACCE

	Unmatched cohort			Matched cohort
	LVDs >42.8 mm (n=77)	LVDs ≤42.8 mm (n=91)	P value	LVDs >42.8 mm (n=62)	LVDs ≤42.8 mm (n=62)	P value
MACCE	22 (28.6)	13 (14.3)	0.026	20 (32.3)	10 (16.1)	0.036
MACCE components
All-cause mortality	6 (7.8)	4 (4.4)	0.368	4 (6.5)	4 (6.5)	1.000
Non-fatal myocardial infarction	0 (0)	0 (0)	–	0 (0)	0 (0)	–
Non-fatal heart failure	12 (15.6)	4 (4.4)	0.019	12 (19.4)	3 (4.8)	0.013
Non-fatal stroke	4 (5.2)	2 (2.2)	0.316	4 (6.5)	2 (3.2)	0.407
Repeat revascularization	0 (0)	3 (3.3)	0.083	0 (0)	1 (1.6)	0.321

Unless indicated otherwise, data are given as n (%). LVDs, left ventricular end-systolic diameter; MACCE, major adverse cardiac and cerebrovascular events.

Figure 1.

Kaplan-Meier estimates of freedom from major adverse cardiac and cerebrovascular events (MACCE) with 95% confidence intervals (shaded area) in the unmatched cohort according to left ventricular end-systolic diameter (LVDs) >42.8 and ≤42.8 mm. Vertical bars indicate the SE.

Figure 2.

Kaplan-Meier estimates of freedom from major adverse cardiac and cerebrovascular events (MACCE) with 95% confidence intervals (shaded area) in the matched cohort according to left ventricular end-systolic diameter (LVDs) >42.8 and ≤42.8 mm. Vertical bars indicate the SE.

The multivariable Cox proportional hazards model showed that independent predictors of MACCE were preoperative LVDs >42.8 mm (hazard ratio [HR] 2.485; 95% confidence interval [CI] 1.239–4.984; P=0.010), previous cerebrovascular disease (HR 3.368; 95% CI 1.254–9.043; P=0.016), and redo surgery (HR 3.930; 95% CI 1.323–11.671; P=0.014; Table 4).

Table 4.

Multivariable Cox Proportional Hazards Model for the Predictors of MACCE

Predictor	HR	95% CI	P value
Previous CVD	3.368	1.254–9.043	0.016
eGFR <60 mL/min/1.73 m2	1.818	0.911–3.627	0.090
Redo surgery	3.930	1.323–11.671	0.014
LVDs >42.8 mm	2.485	1.239–4.984	0.010

CI, confidence interval; HR, hazard ratio. Other abbreviations as in Tables 1,3.

In subgroup analyses, we compared postoperative outcomes between patients with preoperative LVEF <50% and those with preoperative LVEF ≥50%. The adjusted 10-year rate of freedom from MACCE was 74.8% and 79.0% in patients with preoperative LVEF <50% vs. ≥50%, respectively (Supplementary Figure 2). Kaplan-Meier survival analysis indicated no significant differences between these 2 groups (P=0.230). We also compared postoperative outcomes according to preoperative LVDsI (>25 vs. ≤25 mm/m²). The adjusted 10-year rate of freedom from MACCE in the LVDsI >25 and ≤25 mm/m² groups was 76.5% and 79.9%, respectively (Supplementary Figure 3). Kaplan-Meier survival analysis indicated no group differences (P=0.544). We also entered preoperative LVEF <50% and preoperative LVDsI >25 mm/m² into multivariable models in place of LVDs >42.8 mm (Table 5). In this analysis, MACCE was not predicted by either preoperative LVEF <50% (HR 1.436; 95% CI 0.645–3.196; P=0.376) or preoperative LVDsI >25 mm/m² (HR 1.233; 95% CI 0.617–2.468; P=0.553).

Table 5.

Multivariable Cox Proportional Hazards Models for the Predictors of MACCE

Predictor	Model 1			Predictor	Model 2
	HR	95% CI	P value		HR	95% CI	P value
Previous CVD	2.870	1.087–7.582	0.033	Previous CVD	3.015	1.118–8.133	0.029
eGFR <60 mL/min/1.73 m2	1.665	0.797–3.478	0.175	eGFR <60 mL/min/1.73 m2	1.808	0.901–3.629	0.096
Redo surgery	4.350	1.426–13.271	0.010	Redo surgery	4.023	1.342–12.063	0.013
Preoperative LVEF <50%	1.436	0.645–3.196	0.376	LVDsI >25 mm/m2	1.233	0.617–2.468	0.553

LVDsI, left ventricular end-systolic diameter index. Other abbreviations as in Tables 1,3,4.

Left Ventricular Remodeling During Follow-up

In the unweighted cohort, LVEF 5 years after surgery was lower in the group with LVDs >42.8 mm (n=39; 58.4±7.5%) than in the group with LVDs ≤42.8 mm (n=55; 63.5±5.4%; P<0.001). Conversely, LVDd was higher in the group with LVDs >42.8 mm than in the group with LVDs ≤42.8 mm (49.0±4.6 vs. 45.8±4.4 mm, respectively; P=0.001), as were LVDs (34.1±5.0 vs. 30.1±4.4 mm, respectively; P<0.001) and LVMI (128±25 vs. 114±25 g/m², respectively; P=0.007).

In the weighted cohort, 5 years after surgery, LVEF was lower in the group with LVDs >42.8 mm (n=30; 57.5±8.1%) than in the group with LVDs ≤42.8 mm (n=36; 63.7±6.0%; P<0.001). In addition, there were significant differences between the LVDs >42.8 and ≤42.8 mm groups in LVDd (49.2±5.0 vs. 46.3±5.0 mm; P=0.024), LVDs (34.5±5.3 vs. 30.4±5.0 mm; P=0.002), and LVMI (127±27 vs. 113±26 g/m²; P=0.038).

Discussion

To minimize bias related to surgical technique, patients who underwent combined valvular surgery or who underwent coronary bypass grafting were excluded from the present study. In this way, we attempted to isolate the influence of preoperative factors on long-term outcomes. In addition, there were only 4 (2.4%) patients in our entire cohort who had a history of previous percutaneous coronary intervention. Therefore, in this study cohort, the primary cause of LV dilation was AR progression, and ischemic cardiomyopathy was presumed to have little effect.

A major finding of the present study was that the incidence of MACCE was significantly higher in the group with LVDs >42.8 mm than in the group with LVDs ≤42.8 mm. LV dilation has been reported to be associated with poorer postoperative outcomes after AVR,^7,9 and our results confirm these findings. However, the LVDs cut-off value in our study must be interpreted with caution because only Japanese participants were included. A previous study reported low BSA in Japanese populations and small LV chamber size compared with American Society of Echocardiography reference values.¹⁰ Therefore, preoperative LVDs >42.8 mm may not be a suitable predictive factor for AVR in all populations.

AVR is recommended for asymptomatic patients with LVDsI >25 mm/m² as a Class IIa indication in the ACC/AHA guidelines⁴ and as a Class I indication in the ESC/EACTS guidelines.⁵ In the present study, LVDsI >25 mm/m² was not significantly associated with a higher risk of MACCE (P=0.553; Table 5). In our study cohort, mean the BSA was 1.64±0.21 m². Therefore, LVDsI >25 mm/m² was approximately equivalent to LVDs >41 mm in our participants. That is, using LVDsI >25 mm/m² as a cut-off value in our cohort included many people with normal LV size. This may explain why there was no significant difference in the Kaplan-Meier curve estimates for the LVDsI >25 and ≤25 mm/m² groups, and why preoperative LVDsI >25 mm/m² was not significantly associated with a higher risk of MACCE. Our results suggest that it may be necessary to use different LVDs or LVDsI cut-off values depending on body size. Sambola et al investigated postoperative outcomes in 147 patients with chronic AR and concluded that LVDsI >25 mm/m² should be used as a cut-off point for surgery rather than LVDs >50 mm in patients with BSA <1.68 m².¹¹ However, there were only 40 (27.2%) patients with BSA <1.68 m² included in that study. In our cohort, there were 95 (56.5%) patients with BSA <1.68 m². Further research is needed to determine whether LVDs or LVDsI should be used for different body sizes. Our study shows that LVDs >42.8 mm may be more predictive than LVDsI >25 mm/m² in Japanese patients with an average BSA of 1.64 m².

ESC/EACTS⁵ and JCS/JSCS/JATS/JSVS⁶ guidelines state that AVR is recommended for asymptomatic patients with LVEF <50% as a Class I indication. Conversely, AVR is recommended for asymptomatic patients with LVEF <55% as a Class I indication in the ACC/AHA guidelines.⁴ In the present study, there was no evidence of differences in 10-year rates of freedom from MACCE when comparing participants with LVEF <50% to those with LVEF ≥50% (Supplementary Figure 2). In addition, preoperative LVEF <50% was not significantly associated with MACCE in multivariable analysis (P=0.376; Table 5). This result may suggest that preoperative LVDs >42.8 mm is a better predictor of adverse outcomes than preoperative LVEF <50%. LVDs has been reported to be an important index because associated increases in volume preload and afterload are key factors in LV dysfunction and dilation in patients with chronic severe AR.⁶ LVEF is commonly calculated with LV end-systolic volume and LV end-diastolic volume using the Simpson method. AR compensates for heart failure by increasing end-diastolic volume. Therefore, even if LVEF is normal, LV dysfunction may progress. However, LVDs is not easily influenced by other factors because it is an independent value, which may explain why LVDs predicted outcomes better than LVEF in the present study.

At 5 years after surgery, all 4 measures of LV morphology showed improvement from preoperative values. In addition, significant differences in LVDd, LVDs, LVEF, and LVMI continued to be observed between the 2 groups. That is, there was less LV remodeling in the LVDs >42.8 mm group during the follow-up period. LV remodeling has been reported to be associated with improved outcomes after AVR for AR.¹² Therefore, the greater LV remodeling observed in the LVDs ≤42.8 mm group may have contributed to better long-term outcomes. The results of this study suggest that surgery for AR should be performed before LV dilation occurs, also in terms of LV remodeling.

Study Limitations

This study had some limitations. First, the study did not have a prospective or randomized design. Even with propensity score matching, a completely fair comparison between the LVDs >42.8 and ≤42.8 mm groups could not be performed. Second, this was a small cohort study at a single institution in Japan, which may limit the generalizability of our findings. Finally, echographic data 5 years after surgery could only be obtained for 56.0% (94/168) of patients. Therefore, we have to consider a selection bias for differences in LV remodeling between the 2 groups during the follow-up period.

Conclusions

Preoperative LVDs >42.8 mm was significantly associated with increased risk of MACCE in Japanese patients undergoing AVR for AR. Preoperative LVDs >42.8 mm may better predict surgical outcomes than preoperative LVEF <50% or LVDsI >25 mm/m².

Acknowledgment

The authors thank Cami Moss, from Edanz (https://jp.edanz.com/ac), for editing a draft of this manuscript.

Sources of Funding

This study did not receive any specific funding.

Disclosures

The authors have no conflicts of interest to declare.

IRB Information

This study was approved by the Institutional Review Board of Shiga University of Medical Science (Reference no. R2023-090).

Data Availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Supplementary Files

Please find supplementary file(s);

https://doi.org/10.1253/circj.CJ-24-0081

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