# Predictive Value of QRS Fraction for Cardiovascular Death in Patients with Heart Failure: A Prospective Cohort Study in Acute Decompensated Heart Failure (Heb-ADHF)

## TL;DR

This study shows that a simple ECG measurement called QRS fraction can predict cardiovascular death risk in heart failure patients, especially those with preserved ejection fraction.

## Contribution

The study demonstrates that QRS fraction is an independent predictor of cardiovascular mortality in heart failure patients.

## Key findings

- Higher QRS fraction groups (Q2 and Q3) had significantly lower cardiovascular death risk compared to the lowest group (Q1).
- Kaplan-Meier survival curves showed significant differences in mortality among QRS fraction subgroups, particularly in patients with preserved ejection fraction.
- Cox regression analysis confirmed the QRS fraction as an independent predictor of cardiovascular death risk.

## Abstract

The QRS fraction is the ratio of the total amplitude of R
waves to the total amplitude of QRS complexes (∑R/QRS) on a 12-lead
electrocardiogram. Our group has previously proposed calculation of the QRS
fraction as a simple method for estimation of left ventricular ejection fraction.
In this study, we explored the ability of the QRS fraction to predict
cardiovascular death in patients with heart failure.

The study
had a prospective, observational design and collected epidemiological and
follow-up data for 1715 patients with heart failure who were inpatients in the
Department of Cardiology at the Second Hospital of Hebei Medical University
between January 2017 and December 2018. The patients were stratified according to
quartile of QRS fraction, namely, lower (<43.8%, Q1 group)
middle (43.8%–61.0%, Q2 group), and higher (>61.0%, Q3 group).

One thousand and fifty-one (61.28%) of the 1715 patients were
male and the median follow-up duration was 261 days (interquartile range 39,
502). There were 341 (19.88%) deaths, including 282 (16.44%) with a
cardiovascular cause. The Q1, Q2, and Q3 groups comprised 431 (25.13%), 850
(49.56%), and 434 (25.31%) patients, respectively. There were significant
differences in cardiovascular mortality among the three QRS fraction subgroups
(p < 0.05). Kaplan-Meier survival curves of different QRS fraction
levels showed significant diffference among patients with heart failure,
especially among those with preserved ejection fraction (p = 0.025 and
0.031, log-rank test). Cox regression analysis showed that the QRS fraction was
independently associated with the risk of cardiovascular death. The risk of
cardiovascular death was lower in the Q2 and Q3 groups than in the Q1 group, with
respective hazard ratios of 0.668 (95% confidence interval 0.457–0.974) and
0.538 (95% confidence interval 0.341–0.849).

The QRS
fraction may serve as a prognostic indicator of the long-term risk of
cardiovascular death in patients with heart failure, especially those with
preserved ejection fraction.

ChiCTR-POC-17014020.