Prognostic impact of multiple fragmented QRS on cardiac events in idiopathic dilated cardiomyopathy

Abstract

Aims To evaluate the prognostic impact of fragmented QRS (fQRS) on idiopathic dilated cardiomyopathy (DCM). Methods and results We conducted a prospective observational study of 290 consecutive patients with DCM (left ventricular ejection fraction ≤ 40%) and narrow QRS who underwent cardiac magnetic resonance. We defined fQRS as the presence of various RSR′ patterns in ≥2 contiguous leads representing the anterior (V1–V5), inferior (II, III, and aVF), or lateral (I, aVL, and V6) myocardial segments. Multiple fQRS was defined as the presence of fQRS in ≥2 myocardial segments. Patients were divided into three groups: no fQRS, single fQRS, or multiple fQRS. The primary endpoint was a composite of hard cardiac events consisting of heart failure death, sudden cardiac death (SCD), or aborted SCD. The secondary endpoints were all-cause death and arrhythmic event. During a median follow-up of 3.8 years (interquartile range, 1.8–6.2), 31 (11%) patients experienced hard cardiac events. Kaplan–Meier analysis showed that the rates of hard cardiac events and all-cause death were similar in the single-fQRS and no-fQRS groups and higher in the multiple-fQRS group (P = 0.004 and P = 0.017, respectively). Multivariable Cox regression identified that multiple fQRS is a significant predictor of hard cardiac events (hazard ratio, 2.23; 95% confidence interval, 1.07–4.62; P = 0.032). The multiple-fQRS group had the highest prevalence of a diffuse late gadolinium enhancement pattern (no fQRS, 21%; single fQRS, 22%; multiple fQRS, 39%; P < 0.001). Conclusion Multiple fQRS, but not single fQRS, is associated with future hard cardiac events in patients with DCM.

Nomogram predicting death and heart transplantation before appropriate ICD shock in dilated cardiomyopathy

“…As reported, primary prevention was independently associated with a reduced risk of shocks compared with secondary prevention, 12,19,35,37 but no difference in mortality was found. 35,37 It was also found that higher LVEDD and NT-proBNP were related to an increased risk of mortality, 19,26,32 and ACEI/ARB was related to a reduced risk of mortality, 18,20 but none of these was associated with disproportionately increased risk of sudden death. 38 Although our study showed amiodarone decreased the likelihood of death prior to shock, the mechanism was intriguing.…”

“…Prior investigations of risk stratification for ICD recipients are either the risk of occurring ventricular arrhythmias (including VT, VF, and SCD) [26][27][28][29] or death. 6,[30][31][32] Various methods including risk score algorithm based on multivariable regression, 28 landmark analysis, 27 and random forest 26 were applied to evaluate the risk of life-threatening ventricular arrhythmias, and all showed satisfactory performance. Among models predicting survival in heart failure, the Seattle Heart Failure Model (SHFM) 31 was widely recognized.…”

Fragmented QRS as a risk marker for the occurrence of ventricular fibrillation in patients with variant angina

“…shown that the existence of fQRS is a prognostic factor for patients with various organic heart diseases (Haraoka et al, 2010;Luo et al, 2020;Marume et al, 2021;Morita et al, 2017;Peters et al, 2008;Schuller et al, 2011). Das et al found a correlation between fQRS and the presence of a myocardial scar.…”

“…Additionally, the myocardial scar detected by the fQRS wave is strongly associated with ventricular dysfunction and is a substrate for reentrant ventricular arrhythmia including VF. (Pietrasik & Zareba, 2012 ) Furthermore, the fQRS has been postulated to be predictive of outcomes in various organic heart diseases, such as ischemic heart disease, (Luo et al, 2020 ) dilated cardiomyopathy, (Marume et al, 2021 ) arrhythmogenic right ventricular cardiomyopathy, (Peters et al, 2008 ) sarcoidosis, (Schuller et al, 2011 ) Brugada syndrome (Morita et al, 2017 ) and acquired long QT syndrome. (Haraoka et al, 2010 ) Nevertheless, whether the fQRS is involved in the occurrence of VF in VA patients who are not considered to have organic cardiac dysfunction remains unclear.…”

QRS micro-fragmentation as a mortality predictor

“…Prolonged QRS complex duration has long been a recognized risk factor for adverse cardiac events. 1,2 More recently, the socalled QRS complex fragmentation, defined by visually detected splits of QRS waves, 3,4 has also been found to predict poor outcome in both cardiac patients and other well-defined groups [5][6][7] including the general population. 4 This increased risk due to visible QRS fragmentation appears independent of the overall QRS complex duration.…”