NSTEMI accounts for approximately 60–70% of acute coronary syndromes. In the absence of appropriate diagnosis and treatment, it is associated with substantial morbidity and mortality.
Revascularization improves survival; however, current clinical guidelines primarily focus on percutaneous coronary intervention (PCI), despite the fact that nearly 10% of NSTEMI patients ultimately undergo surgical revascularization (CABG). The recommendation for early revascularization (<24 h) in high-risk patients has recently been downgraded from class I to class IIa (level of evidence A). Nevertheless, although not explicitly stated, the evidence supporting this recommendation is largely derived from studies centered on percutaneous revascularization rather than surgery.
Given this gap in evidence and guideline recommendations, the authors proposed a straightforward hypothesis: does early surgical revascularization result in higher mortality rates compared with delayed CABG?
The study is based on a multicenter retrospective analysis from the Virginia Cardiac Services Quality Initiative, which includes 17 hospitals across the state of Virginia. A total of 10.271 patients who underwent CABG following NSTEMI between 2011 and 2023 were analyzed. For the purpose of the analysis, patients were stratified into three groups according to the time from coronary angiography to surgery: ≤2 days, 3–7 days, and 8–30 days. Operative mortality and major complications (stroke, renal failure, prolonged mechanical ventilation, deep sternal wound infection, or reoperation) were evaluated, with risk adjustment performed using multivariable models.
Key characteristics of the cohort included a mean age of 64 years, a mean cardiopulmonary bypass time of 97 minutes, and a mean aortic cross-clamp time of 72 minutes. The mean STS predicted risk of mortality ranged from 1.3% to 2%. Average intensive care unit (ICU) length of stay was 52, 51, and 65 hours for the ≤2-day, 3–7-day, and 8–30-day groups, respectively. Approximately 50% of procedures were performed at high-volume centers (>450 CABG procedures per year). As expected in a nonrandomized design, significant differences were observed across nearly all baseline variables among the study groups.
Operative mortality differed significantly between groups: 3.2% in the ≤2-day group, 1.79% in the 3–7-day group, and 3.98% in the 8–30-day group. These differences persisted after risk adjustment. Compared with surgery within ≤2 days, CABG performed at 3–7 days was associated with a significantly lower risk of mortality (OR = 0.56; p < .001). Similarly, surgery at 3–7 days was associated with lower mortality compared with the 8–30-day group (OR = 0.51; p < .001). These findings were consistent with the observed rates of major complications: 14% for ≤2 days, 11.4% for 3–7 days, and 16.3% for 8–30 days.
Based on these results, the authors conclude that the optimal timing for CABG after coronary angiography in patients with NSTEMI appears to fall between the third and seventh day.
By analyzing a large cohort and incorporating multiple variables, the study identified several independent risk factors associated with increased morbidity and mortality, including left main coronary artery disease, cardiogenic shock, treatment with ADP inhibitors, peripheral arterial disease, and chronic obstructive pulmonary disease.
COMMENTARY:
Waiting times prior to surgical intervention in patients with NSTEMI are a subject of debate in most hospitals. Despite this, high-quality evidence addressing this issue remains scarce. Why is this the case?
One likely explanation is that, in many instances, the timing of surgery is not a matter of free choice. Multiple factors influence decision-making, including logistical and organizational constraints, the patient’s clinical condition, and administered medical therapies such as antiplatelet treatment.
In this context, and in light of the study findings, it seems reasonable to assume that patients with NSTEMI can safely wait several days before undergoing surgical revascularization, particularly when there are clear clinical or logistical reasons to do so. This decision must be carefully balanced between the stability of the clinical presentation (recurrent angina, presence or absence of ischemic electrocardiographic changes, severity of coronary anatomy, feasibility of percutaneous bailout strategies, and available antianginal therapeutic margin) and the opportunity to optimize the patient’s condition to ensure the best possible status at the time of surgery.
The concept of intervening surgically between days 3 and 7 after NSTEMI is a longstanding dogma that this study effectively reinforces. Indeed, at clinical presentation with non–ST-segment elevation acute coronary syndrome, the presence or absence of myocardial infarction plays a critical role in determining surgical timing, alongside the previously mentioned factors. Paradoxically, it appears counterintuitive that patients with documented myocardial infarction are often required to wait longer than those presenting with acute coronary syndrome without significant myocardial injury.
These principles stem from classic retrospective studies that reached similar conclusions and are now reaffirmed in the context of contemporary clinical practice. However, such designs inherently carry important limitations. To firmly establish these practices, more robust study designs, ideally randomized trials, would be required—data that remain limited at present.
The study discussed here partially addresses this issue, albeit with the intrinsic limitations of a retrospective analysis. Information regarding the incidence of reinfarction, arrhythmias, or death during the waiting period would have further strengthened the evaluation of clinically relevant events influencing decision-making. Nevertheless, it is worth noting that among patients with surgically amenable coronary anatomy, the rate of clinical destabilization while awaiting revascularization after NSTEMI is approximately 0.1%, compared with nearly 10% for excessive bleeding complications—representing a 100-fold greater harm—associated with insufficient discontinuation of dihydropyridine antiplatelet therapy. In this regard, drug removal strategies such as Cytosorb® could potentially shift this paradigm.
Before concluding, it is important to highlight some of the study’s most relevant limitations, while also emphasizing the value of this type of analysis in identifying risk factors (which should not be confused with modifiable risk determinants), many of which are already well described.
Therefore, despite its substantial limitations, the available data suggest that neither extreme urgency nor excessive delay in surgical revascularization is supported by observational evidence. Key factors such as cardiogenic shock or ongoing antiplatelet therapy should be taken into account to individualize decision-making.
REFERENCE:
Norman AV, Weber MP, El Moheb M, Wisniewski AM, Strobel RJ, Speir A, et al. Ideal Timing of Coronary Artery Bypass Grafting After Non–ST-Segment Elevation Myocardial Infarction. Ann Thorac Surg. 2025;120:321-8. doi:10.1016/j.athoracsur.2025.01.024.
