Hypertrophic Cardiomyopathy in Adults and CV Mortality
Background Hypertrophic cardiomyopathy (HCM) has been prominently associated with adverse disease complications, including sudden death or heart failure death and a generally adverse prognosis, with annual mortality rates of up to 6%.
Objectives This study determined whether recent advances in management strategy, including implantable cardioverter-defibrillators (ICDs), heart transplantation, or other therapeutic measures have significantly improved survival and the clinical course of adult HCM patients.
Methods We addressed long-term outcomes in 1,000 consecutive adult HCM patients presenting at 30 to 59 years of age (mean 45 ± 8 years) over 7.2 ± 5.2 years of follow-up.
Results Of 1,000 patients, 918 (92%) survived to 53 ± 9.2 years of age (range 32 to 80 years) with 91% experiencing no or only mild symptoms at last evaluation. HCM-related death occurred in 40 patients (4% [0.53%/year]) at 50 ± 10 years from the following events: progressive heart failure (n = 17); arrhythmic sudden death (SD) (n = 17); and embolic stroke (n = 2). In contrast, 56 other high-risk patients (5.6%) survived life-threatening events, most commonly with ICD interventions for ventricular tachyarrhythmias (n = 33) or heart transplantation for advanced heart failure (n = 18 [0.79%/year]). SD occurred in patients who declined ICD recommendations, had evaluations before application of prophylactic ICDs to HCM, or were without conventional risk factors. The 5- and 10-year survival rates (confined to HCM deaths) were 98% and 94%, respectively, not different from the expected all-cause mortality in the general U.S. population (p = 0.25). Multivariate independent predictors of adverse outcome were younger age at diagnosis, female sex, and increased left atrial dimension.
Conclusions In a large longitudinally assessed adult HCM cohort, we have demonstrated that contemporary management strategies and treatment interventions, including ICDs for SD prevention, have significantly altered the clinical course, now resulting in a low disease-related mortality rate of 0.5%/year and an opportunity for extended longevity.
Hypertrophic cardiomyopathy (HCM) has been historically associated with substantial morbidity and mortality and impaired longevity due to sudden death (SD) and complications of heart failure. However, the previous 15 years have witnessed the emergence of innovative nonpharmacological cardiovascular management strategies for HCM patients, including an expanded risk stratification algorithm, use of implantable cardioverter-defibrillators (ICDs) for SD prevention, and advances in refractory heart failure therapies, including heart transplantation.
Nevertheless, there is limited objective evidence available supporting a cardiovascular mortality benefit attributable to contemporary management options within established HCM cohorts, and some uncertainty may persist in the practicing community. Generally, in adult cardiovascular practice, patients between 30 and 59 years of age (midlife) with HCM constitute the subgroup most commonly presenting for clinical evaluation and are frequently subject to adverse complications. Therefore, we have taken this opportunity to assemble longitudinal cohort data in 1,000 adult patients presenting in this midlife age group to determine the extent to which therapeutic interventions have altered clinical course.
Abstract and Introduction
Abstract
Background Hypertrophic cardiomyopathy (HCM) has been prominently associated with adverse disease complications, including sudden death or heart failure death and a generally adverse prognosis, with annual mortality rates of up to 6%.
Objectives This study determined whether recent advances in management strategy, including implantable cardioverter-defibrillators (ICDs), heart transplantation, or other therapeutic measures have significantly improved survival and the clinical course of adult HCM patients.
Methods We addressed long-term outcomes in 1,000 consecutive adult HCM patients presenting at 30 to 59 years of age (mean 45 ± 8 years) over 7.2 ± 5.2 years of follow-up.
Results Of 1,000 patients, 918 (92%) survived to 53 ± 9.2 years of age (range 32 to 80 years) with 91% experiencing no or only mild symptoms at last evaluation. HCM-related death occurred in 40 patients (4% [0.53%/year]) at 50 ± 10 years from the following events: progressive heart failure (n = 17); arrhythmic sudden death (SD) (n = 17); and embolic stroke (n = 2). In contrast, 56 other high-risk patients (5.6%) survived life-threatening events, most commonly with ICD interventions for ventricular tachyarrhythmias (n = 33) or heart transplantation for advanced heart failure (n = 18 [0.79%/year]). SD occurred in patients who declined ICD recommendations, had evaluations before application of prophylactic ICDs to HCM, or were without conventional risk factors. The 5- and 10-year survival rates (confined to HCM deaths) were 98% and 94%, respectively, not different from the expected all-cause mortality in the general U.S. population (p = 0.25). Multivariate independent predictors of adverse outcome were younger age at diagnosis, female sex, and increased left atrial dimension.
Conclusions In a large longitudinally assessed adult HCM cohort, we have demonstrated that contemporary management strategies and treatment interventions, including ICDs for SD prevention, have significantly altered the clinical course, now resulting in a low disease-related mortality rate of 0.5%/year and an opportunity for extended longevity.
Introduction
Hypertrophic cardiomyopathy (HCM) has been historically associated with substantial morbidity and mortality and impaired longevity due to sudden death (SD) and complications of heart failure. However, the previous 15 years have witnessed the emergence of innovative nonpharmacological cardiovascular management strategies for HCM patients, including an expanded risk stratification algorithm, use of implantable cardioverter-defibrillators (ICDs) for SD prevention, and advances in refractory heart failure therapies, including heart transplantation.
Nevertheless, there is limited objective evidence available supporting a cardiovascular mortality benefit attributable to contemporary management options within established HCM cohorts, and some uncertainty may persist in the practicing community. Generally, in adult cardiovascular practice, patients between 30 and 59 years of age (midlife) with HCM constitute the subgroup most commonly presenting for clinical evaluation and are frequently subject to adverse complications. Therefore, we have taken this opportunity to assemble longitudinal cohort data in 1,000 adult patients presenting in this midlife age group to determine the extent to which therapeutic interventions have altered clinical course.