Age-related differences in ventricular remodeling and long-term heart failure outcomes following acute coronary syndrome
Abstract Background Older patients are at increased risk of heart failure hospitalization following acute coronary syndrome (ACS). Purpose We sought to determine whether this increased hazard was related to differing patterns in left ventricular (LV) remodeling over the first 12 months after ACS. Methods In a prospective multi-centre observational cohort study, 2,140 patients with ACS underwent echocardiography at 1, 4, and 12 months following the index event. Long-term heart failure hospitalisation events were captured for a median 4.8 (IQR 3.4–6.5) years and the relative risk compared between individuals ≤65 years and those >65 years using a multivariable Cox model adjusted for baseline clinical (sex, blood pressure, coronary revascularisation) and echocardiographic (LV end diastolic and end systolic volumes, LV ejection fraction, interventricular septal wall thickness, and E/e') variables recorded at baseline and 12 months. Results The 1177 (55%) participants who were >65 years were more likely to be women (34% versus 22%), had higher blood pressure, were more likely to present with non-ST elevation ACS, demonstrated smaller increases in peak myocardial biomarkers and were less likely to undergo coronary revascularization during the index admission (43.2% versus 72.3%; p<0.001 for all comparisons). At the 1 month visit, after indexing for body surface area, older patients had similar LV end diastolic but larger end systolic volumes (p=0.029), lower LV ejection fractions, and greater left ventricular mass and diastolic filling pressure estimates (E/e' 14 versus 10; p<0.001 for all) compared with the young. Systolic volumes appeared to further diverge at 12 months (p=0.064) however LV mass did not change in either group. In unadjusted analysis older patients were at increased risk of future heart failure hospitalization (HR 4.1, 95% CI 3.2–5.3). This increased risk persisted after adjustment for differences in baseline clinical and echocardiography data, and LV remodeling (adjusted HR 2.4, 95% CI 1.5–3.9). Conclusions Older patients experience a more eccentric remodeling pattern over the 12 months following ACS. Older individuals remain at increased risk of long-term heart failure hospitalization after accounting for clinical and echocardiographic characteristics. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): New Zealand Heart Foundation, New Zealand Health Research Council