Non-ST-Segment Elevation Myocardial Infarction Cohort Reveals High Risk in Patients Without Revascularization
In a real-world cohort of 1,906 patients undergoing coronary angiography for non-ST-segment elevation myocardial infarction (NSTEMI), approximately half were managed without index revascularization, according to data published by MDPI. This subgroup exhibited the highest baseline clinical risk, alongside higher unadjusted in-hospital major adverse cardiac events (MACE) and mortality rates compared to patients who underwent percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).
Baseline Clinical Risk and Treatment Pathways
Patients who received no index revascularization were older, presented with a higher prevalence of chronic kidney disease (CKD), and showed lower left ventricular ejection fraction (LVEF) values. Because every patient in the cohort underwent coronary angiography, the absence of revascularization reflects the lack of subsequent intervention after diagnostic imaging rather than an initially conservative strategy. Advanced age, comorbidity burden, and anatomical complexity frequently dictate whether clinicians pursue revascularization in routine clinical practice.
By contrast, patients directed to CABG demonstrated a higher prevalence of multivessel disease and left main coronary artery (LMCA) involvement. These stark anatomical and clinical differences across management pathways emphasize the presence of confounding by indication.
Multivariable Predictors of In-Hospital Major Adverse Cardiac Events
In the primary multivariable analysis conducted by researchers, CKD emerged as the strongest independent factor associated with in-hospital MACE, yielding an odds ratio of 3.70. Renal dysfunction drives adverse outcomes in acute coronary syndrome through uremic-toxin-mediated myocardial injury, anemia, volume overload, and endothelial dysfunction. Lower LVEF also showed an independent association with in-hospital MACE, with an odds ratio of 0.97, while Killip class 2 or higher more than doubled the odds of adverse events.
Systemic inflammation, measured via C-reactive protein (CRP), demonstrated an independent association with in-hospital MACE at an odds ratio of 1.06 per 1 mg/L increase. Notably, neither PCI nor CABG showed an independent association with MACE in the primary multivariable model once researchers adjusted for baseline risk factors.
Frequent Comorbidities and Diagnostic Subgroups
Renal vulnerability heavily skewed the unadjusted outcomes. The no index revascularization group recorded a CKD prevalence of 19.9%, compared to 5.7% in the PCI group and 4.2% in the CABG group. Furthermore, 181 patients—representing 19.1% of the no index revascularization group—met the study definition for myocardial infarction with non-obstructive coronary arteries (MINOCA). Sensitivity analyses excluding patients with MINOCA did not alter the core associations between final management strategies and in-hospital MACE.
Frequently Asked Questions
What drove the higher MACE rate in the no index revascularization group?
The 9.8% MACE rate in the unadjusted no index revascularization group was driven primarily by all-cause mortality and cardiac arrest requiring cardiopulmonary resuscitation, whereas stroke and sustained ventricular tachycardia or fibrillation did not differ significantly across groups.
How did researchers handle missing peak troponin data?
Peak troponin values were excluded from the primary multivariable model due to a 45.4% missingness rate and potential temporal relationships with in-hospital treatment, though they were evaluated separately in multiple imputation sensitivity analyses.
What surgical grafting characteristics defined the CABG cohort?
Surgical revascularization in this cohort featured left internal mammary artery (LIMA) use in 90.0% of CABG patients, while right internal mammary artery (RIMA) use was documented in only two patients.