Subclinical Cardiovascular Disease and Fall Risk in Older Adults: Results From the Atherosclerosis Risk in Communities Study

Abstract

Background/objectives: Falls are frequent and often devastating events among older adults. Cardiovascular disease (CVD) is associated with greater fall risk; however, it is unknown if pathways that contribute to CVD, such as subclinical myocardial damage or wall strain, are related to future falls. We hypothesized that elevations in high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP), measured in older adults, would be associated with greater fall risk.

Design: Prospective cohort study.

Setting and participants: Atherosclerosis Risk in Communities Study participants without known coronary heart disease, heart failure, or stroke.

Measurements: We measured hs-cTnT or NT-proBNP in 2011 to 2013. Falls were identified from hospital discharge International Classification of Diseases, Ninth Revision (ICD-9), codes or Centers for Medicare and Medicaid Services claims. We used Poisson models adjusted for age, sex, and race/study center to quantify fall rates across approximate quartiles of hs-cTnT (less than 8, 8-10, 11-16, and 17 or greater ng/L) and NT-proBNP (less than 75, 75-124, 125-274, and 275 or greater pg/mL). We used Cox models to determine the association of cardiac markers with fall risk, adjusted for age, sex, race/center, and multiple fall risk factors.

Results: Among 3973 participants (mean age = 76 ± 5 years, 62% women, 22% black), 457 had a subsequent fall during a median follow-up of 4.5 years. Incidence rates across quartiles of hs-cTnT and NT-proBNP were 17.1, 20.0, 26.2, and 36.4 per 1000 person-years and 12.8, 22.2, 28.7, and 48.4 per 1000 person-years, respectively. Comparing highest vs lowest quartiles of either hs-cTnT or NT-proBNP demonstrated a greater than two-fold higher fall risk, with hazard ratios of 2.17 (95% confidence interval {CI} = 1.60-2.95) and 2.34 (95% CI = 1.73-3.16), respectively. In a joint model, the relationships of hs-cTnT and NT-proBNP with falls were significant and independent.

Conclusion: Subclinical elevations of cardiac damage and wall strain were each associated with a higher fall risk in older adults. Further research is needed to determine whether interventions that lower hs-cTnT or NT-proBNP also lower fall risk. J Am Geriatr Soc 67:1795-1802, 2019.

Keywords: N-terminal pro-B-type natriuretic peptide; cardiovascular disease; cohort; falls; high sensitivity cardiac troponin T.

Figure 1.

Kaplan-Meier cumulative incidence plot with follow-up years as the time axis and falls as the outcome stratified by categories of (A) high sensitivity troponin T (hs-cTnT, ng/L) or (B) N-terminal pro b-type natriuretic peptide (NT-proBNP, pg/mL) measured in plasma at baseline (visit 5). A logrank test was performed to assess for a trend across categories.

Figure 2.

Adjusted hazard ratios (solid line) for falls according to plasma concentration of (A) high sensitivity troponin T (hs-cTnT, ng/L) or (B) N-terminal pro b-type natriuretic peptide (NT-proBNP, pg/mL), using a restricted cubic spline with 4 knots determined by Harrell’s method. Gray shade represents 95% confidence intervals. Both models were expressed relative to the median value and were right-tail truncated at the 95^th percentile. Models were adjusted for age, sex, race-study center, estimated glomerular filtration rate, body mass index, stage 2 hypertension status, seated systolic blood pressure, seated diastolic blood pressure, diabetes status, drinking status, smoking status, hypertension medication use in last two weeks, diuretic use, antidepressant use, sedative use, hypnotic use, antipsychotic use, and anticholinergic use. The hazard ratios are shown on a natural log scale. Included are histograms of hs-cTnT or NT-proBNP.