2021 Volume 41 Issue 2 Pages 64-73
The association between first-degree atrioventricular block（AVB）and life-threatening cardiac events in patients with hypertrophic cardiomyopathy（HCM）remains unclear. This study sought to investigate whether the presence of first-degree AVB was associated with HCM-related death in patients with HCM. We included 414 patients with HCM（mean age 51±16 years, 64.5％ men）. The P-R interval was measured at the time of the initial evaluation and patients were classified into those with and without first-degree AVB, which was defined as a P-R interval ≧200 milliseconds. HCM-related death was defined as a combined endpoint of sudden death or potentially lethal arrhythmic events, heart failure-related death, and stroke-related death. First-degree AVB was noted in 96 patients（23.2％）at the time of enrollment. Over a median（IQR）follow-up period of 8.8（4.9-12.9）years, a total of 56 patients（13.5％）experienced HCM-related deaths including 47（11.4％）with a combined endpoint of sudden death or potentially lethal arrhythmic events. In a multivariable analysis that included first-degree AVB and risk factors for life-threatening events, first-degree AVB was independently associated with an HCM-related death（adjusted hazard ratio［HR］ : 2.41 ; 95％ confidence interval ［CI］ : 1.27-4.58 ; p＝0.007）and this trend also persisted for the combined endpoint of sudden death or potentially lethal arrhythmic events（adjusted HR : 2.60 ; 95％ CI : 1.28-5.27 ; p＝0.008）. In this cohort of patients with HCM, first-degree AVB may be associated with HCM-related death, including the combined endpoint of sudden death or potentially lethal arrhythmic events.
