Background: Cancer therapy–induced cardiomyopathy (CCM) is associated with cumulative drug exposures and preexisting cardiovascular disorders. These parameters incompletely account for substantial interindividual susceptibility to CCM. We hypothesized that rare variants in cardiomyopathy genes contribute to CCM. Methods: We studied 213 patients with CCM from 3 cohorts: retrospectively recruited adults with diverse cancers (n=99), prospectively phenotyped adults with breast cancer (n=73), and prospectively phenotyped children with acute myeloid leukemia (n=41). Cardiomyopathy genes, including 9 prespecified genes, were sequenced. The prevalence of rare variants was compared between CCM cohorts and The Cancer Genome Atlas participants (n=2053), healthy volunteers (n=445), and an ancestry-matched reference population. Clinical characteristics and outcomes were assessed and stratified by genotypes. A prevalent CCM genotype was modeled in anthracycline-treated mice. Results: CCM was diagnosed 0.4 to 9 years after chemotherapy; 90% of these patients received anthracyclines. Adult patients with CCM had cardiovascular risk factors similar to the US population. Among 9 prioritized genes, patients with CCM had more rare protein-altering variants than comparative cohorts ( P ≤1.98e–04). Titin-truncating variants (TTNtvs) predominated, occurring in 7.5% of patients with CCM versus 1.1% of The Cancer Genome Atlas participants ( P =7.36e–08), 0.7% of healthy volunteers ( P =3.42e–06), and 0.6% of the reference population ( P =5.87e–14). Adult patients who had CCM with TTNtvs experienced more heart failure and atrial fibrillation ( P =0.003) and impaired myocardial recovery ( P =0.03) than those without. Consistent with human data, anthracycline-treated TTNtv mice and isolated TTNtv cardiomyocytes showed sustained contractile dysfunction unlike wild-type ( P =0.0004 and P <0.002, respectively). Conclusions: Unrecognized rare variants in cardiomyopathy-associated genes, particularly TTNtvs, increased the risk for CCM in children and adults, and adverse cardiac events in adults. Genotype, along with cumulative chemotherapy dosage and traditional cardiovascular risk factors, improves the identification of patients who have cancer at highest risk for CCM. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifiers: NCT01173341; AAML1031; NCT01371981.

Background: Although frailty has been associated with increased risks for hospitalization and mortality in chronic heart failure, the precise average effect remains uncertain. We performed a systematic review and meta‐analysis to summarize the hazards for mortality and incident hospitalization in patients with heart failure and frailty compared with those without frailty and explored the heterogeneity underlying the effect size estimates. Methods and Results: MEDLINE , EMBASE, and Cochrane databases were queried for articles published between January 1966 and March 2018. Predefined selection criteria were used. Hazard ratios ( HRs ) were pooled for meta‐analyses, and where odds ratios were used previously, original data were recalculated for HR . Overlapping data were consolidated, and only unique data points were used. Study quality and bias were assessed. Eight studies were included for mortality (2645 patients), and 6 studies were included for incident hospitalization (2541 patients) during a median follow‐up of 1.82 and 1.12 years, respectively. Frailty was significantly associated with an increased hazard for mortality ( HR , 1.54; 95% confidence interval, 1.34–1.75; P <0.001) and incident hospitalization ( HR , 1.56; 95% confidence interval, 1.36–1.78; P <0.001) in chronic heart failure. The Fried phenotype estimated a 16.9% larger effect size than the combined Fried/non‐Fried frailty assessment for the end point of mortality ( HR , 1.80; 95% confidence interval, 1.41–2.28; P <0.001), but not for hospitalization ( HR , 1.57; 95% confidence interval, 1.30–1.89; P <0.001). Study heterogeneity was found to be low (I ² =0%), and high quality of studies was verified by the Newcastle‐Ottawa scale. Conclusions: Overall, the presence of frailty in chronic heart failure is associated with an increased hazard for death and hospitalization by ≈1.5‐fold.

Background: Most patients with chronic heart failure have detectable troponin concentrations when evaluated by high-sensitivity assays. The prognostic relevance of this finding has not been clearly established so far. We aimed to assess high-sensitivity troponin assay for risk stratification in chronic heart failure through a meta-analysis approach. Methods: Medline, EMBASE, Cochrane Library, and Scopus were searched in April 2017 by 2 independent authors. The terms were “troponin” AND “heart failure” OR “cardiac failure” OR “cardiac dysfunction” OR “cardiac insufficiency” OR “left ventricular dysfunction.” Inclusion criteria were English language, clinical stability, use of a high-sensitivity troponin assay, follow-up studies, and availability of individual patient data after request to authors. Data retrieved from articles and provided by authors were used in agreement with the PRISMA statement. The end points were all-cause death, cardiovascular death, and hospitalization for cardiovascular cause. Results: Ten studies were included, reporting data on 11 cohorts and 9289 patients (age 66±12 years, 77% men, 60% ischemic heart failure, 85% with left ventricular ejection fraction <40%). High-sensitivity troponin T data were available for all patients, whereas only 209 patients also had high-sensitivity troponin I assayed. When added to a prognostic model including established risk markers (sex, age, ischemic versus nonischemic etiology, left ventricular ejection fraction, estimated glomerular filtration rate, and N-terminal fraction of pro-B-type natriuretic peptide), high-sensitivity troponin T remained independently associated with all-cause mortality (hazard ratio, 1.48; 95% confidence interval, 1.41–1.55), cardiovascular mortality (hazard ratio, 1.40; 95% confidence interval, 1.33–1.48), and cardiovascular hospitalization (hazard ratio, 1.42; 95% confidence interval, 1.36–1.49), over a median 2.4-year follow-up (all P <0.001). High-sensitivity troponin T significantly improved risk prediction when added to a prognostic model including the variables above. It also displayed an independent prognostic value for all outcomes in almost all population subgroups. The area under the curve–derived 18 ng/L cutoff yielded independent prognostic value for the 3 end points in both men and women, patients with either ischemic or nonischemic etiology, and across categories of renal dysfunction. Conclusions: In chronic heart failure, high-sensitivity troponin T is a strong and independent predictor of all-cause and cardiovascular mortality, and of hospitalization for cardiovascular causes, as well. This biomarker then represents an additional tool for prognostic stratification.