Background: QRS duration is considered to be an indicator of adverse outcome in patients with heart failure (HF), and genetic polymorphisms may be involved in this conductivity impairment. We studied the prognostic impact of the QRS widening rate (QRS-WR) on patients with HF and the influence of the matrix metalloproteinases gene polymorphisms on the QRS-WR.
Methods: This prospective cohort study included 184 patients with left ventricular (LV) systolic dysfunction (LV ejection fraction [LVEF] < 45%). The QRS-WR was calculated as the difference between 2 electrocardiogram assessments (in ms) divided by the time elapsed between each evaluation (months). The MMP-1 -1607 1G/2G, MMP-2 -790G/T and -1575G/A, MMP-3 -1171 5A/6A, MMP-9 -1562 C/T and R279Q, and MMP-12 -82A/G polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism.
Results: Patients were predominantly white (68%) men (67%) in New York Heart Association functional classes I and II (77%). Patients with HF with a QRS-WR ≥ 0.5 ms/month had more HF-related deaths and more combined clinical events than those with a QRS-WR < 0.5 ms/month (P = 0.03 and P = 0.01, respectively). After adjusting for other covariates, the QRS-WR remained an independent predictor of combined clinical events (hazard ratio, 1.6; 95% confidence interval, 1.1-2.5; P = 0.02). The MMP-1 2G2G genotype was associated with nearly a 2-fold increase in QRS-WR (P = 0.03). Conversely, patients with the MMP-3 5A5A genotype and a nonischemic cause of HF were protected against QRS enlargement (P = 0.03).
Conclusions: QRS-WR retains prognostic value in patients with chronic HF receiving guideline-based pharmacologic treatment. MMP gene polymorphisms can influence the rate of QRS enlargement over time.
Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.