Prolonged QRS duration in NSTEMI patients not tied to worse MACE and in-hospital death: Study

Emerging evidence has suggested that prolonged QRSd is linked with increased short-term mortality in STEMI patients. The QRS duration has been demonstrated to have a significant prognostic impact, and in patients with heart failure, it independently predicts adverse outcomes. Patients with NSTEMI represent a heterogenous group that has similar consequences as presented by STEMI patients.

QRSd is under-researched and ill-defined as a prognosticator in NSTEMI patients. Several small studies have shown an adverse relation between QRSd and mortality outcomes. However, these findings have only been authenticated in small cohorts with a maximum of 2,000 patients.

Considering the above, Saadiq M. Moledina, Division of Cardiology, Royal Stoke University Hospital, Staffordshire, United Kingdom, and colleagues therefore, aimed to examine the management strategies, characteristics, outcomes, and quality of care of patients by QRSd.

The researchers analyzed hospitalizations of 240,866 adults (≥18 years) with NSTEMI by extracting data from the United Kingdom Myocardial Infarction National Audit Project. Thirty-eight thousand twenty-three patients presented with a QRSd >120 ms and 202,842 patients with a QRSd <120 ms. All-cause in-hospital mortality and clinical characteristics were analyzed per QRSd.

The study yielded the following findings:

• Patients having QRSd >120 ms were more commonly older (median age of 79 years vs. 71 years) and of white ethnicity (93% vs. 91%).
• Patients having QRSd <120 ms had higher frequency of use of aspirin (97% vs 95%), P2Y12 inhibitor (93% vs 89%), angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (82% vs 81%) and β blockers (83% vs 78%).
• Invasive management strategies were more probable to be used in patients with QRSd <120 ms, including invasive coronary angiography (72% vs. 54%), percutaneous coronary intervention (46% vs. 33%), and coronary artery bypass graft surgery (8% vs. 6%).
• In a propensity score matching analysis, there were no differences between the two groups in the adjusted rates of in-hospital all-cause mortality (odds ratio 0.94) or major adverse cardiac events (odds ratio 0.94) during the index admission.

"We found that patients with a QRSd >120 ms were most commonly men, older, of Black ethnicity, and multi-morbidity with a history of a previous PCI, MI, or CABG surgery," the researchers wrote. "They were less frequently discharged on guideline-directed medication and were treated invasively less frequently. Elongated QRSd >120 ms in the NSTEMI context is not tied to worse MACE outcomes or in-hospital mortality."

Reference:

Moledina SM, Mannan F, Weight N, Alisiddiq Z, Elbadawi A, Elgendy IY, Fischman DL, Mamas MA. Impact of QRS Duration on Non-ST-Segment Elevation Myocardial Infarction (from a National Registry). Am J Cardiol. 2022 Sep 11:S0002-9149(22)00856-6. doi: 10.1016/j.amjcard.2022.07.039. Epub ahead of print. PMID: 36100505.