Incremental value of global longitudinal strain in the long-term prediction of heart failure among patients with coronary artery disease

Background
Heart failure (HF) remains a common complication for patients with coronary artery disease (CAD), especially after acute myocardial infarction. Although left ventricular ejection fraction (LVEF) is conventionally used to assess cardiac function for risk stratification, it has been shown in other settings to underestimate the risk of HF compared with global longitudinal strain (GLS). Moreover, most evidence pertains to early-onset HF. We sought the clinical and myocardial predictors for late-onset HF in patients with CAD.

Methods
We analyzed echocardiograms (including GLS) in 334 patients with CAD (ages 65 ± 11 years, 77% male) who were enrolled in the Nurse-Led Intervention for Less Chronic Heart Failure trial, a prospective, randomized controlled trial that compared standard care with nurse-led intervention to prevent HF in individuals at risk of incident HF. Long-term (9 years) follow-up was obtained via data linkage. Analysis was performed using a competing-risk model.

Results
Baseline LVEF values were normal or mildly impaired (LVEF ≥ 40%) in all subjects. After a median of 9 years of follow-up, 50 (15%) of the 334 patients had new HF admissions, and 68 (20%) died. In a competing-risk model, HF was associated with GLS (hazard ratio = 1.15 [1.05-1.25], P = .001), independent of estimated glomerular filtration rate (hazard ratio = 0.98 [0.97-0.99], P = .045), Charlson comorbidity score (hazard ratio = 1.64 [1.25-2.15], P < .001), or E/e’ (hazard ratio = 1.08 [1.02-1.14], P = .01). Global longitudinal strain—but not conventional echocardiographic measures—added incremental value to a clinical model based on age, gender, and Charlson score (area under the curve, 0.78-0.83, P = .01). Global longitudinal strain was still associated with HF development in patients taking baseline angiotensin convertase enzyme inhibitors (hazard ratio = 1.21 [1.11-1.31], P < .01) and baseline beta-blockers (1.17 [1.09, 1.26]; P < .01). Mortality was associated with older men, risk factors (hypertension or diabetes), and comorbidities (AF and chronic kidney disease).

Conclusions
Global longitudinal strain is independently associated with risk of incident HF in patients admitted with CAD and provides incremental prognostic value to standard markers. Identifying an at-risk subgroup using GLS may be the focus of future randomized controlled trails to enable targeted therapeutic intervention.