Diagnosis and Prognostic Value of the Underlying Cause of Acute Coronary Syndrome in Optical Coherence Tomography-Guided Emergency Percutaneous Coronary Intervention

Abstract

Background The prognostic impact of optical coherence tomography-diagnosed culprit lesion morphology in acute coronary syndrome (ACS) has not been systematically examined in real-world settings. Methods and Results This investigator-initiated, prospective, multicenter, observational study was conducted at 22 Japanese hospitals to identify the prevalence of underlying ACS causes (plaque rupture [PR], plaque erosion [PE], and calcified nodules [CN]) and their impact on clinical outcomes. Patients with ACS diagnosed within 24 hours of symptom onset undergoing emergency percutaneous coronary intervention were enrolled. Optical coherence tomography-guided percutaneous coronary intervention recipients were assessed for underlying ACS causes and followed up for major adverse cardiac events (cardiovascular death, myocardial infarction, heart failure, or ischemia-driven revascularization) at 1 year. Of 1702 patients with ACS, 702 (40.7%) underwent optical coherence tomography-guided percutaneous coronary intervention for analysis. PR, PE, and CN prevalence was 59.1%, 25.6%, and 4.0%, respectively. One-year major adverse cardiac events occurred most frequently in patients with CN (32.1%), followed by PR (12.4%) and PE (6.2%) (log-rank P<0.0001), primarily driven by increased cardiovascular death (CN, 25.0%; PR, 0.7%; PE, 1.1%; log-rank P<0.0001) and heart failure trend (CN, 7.1%; PR, 6.8%; PE, 2.2%; log-rank P<0.075). On multivariate Cox regression analysis, the underlying ACS cause was associated with 1-year major adverse cardiac events (CN [hazard ratio (HR), 4.49 [95% CI, 1.35-14.89], P=0.014]; PR (HR, 2.18 [95% CI, 1.05-4.53], P=0.036]; PE as reference). Conclusions Despite being the least common, CN was a clinically significant underlying ACS cause, associated with the highest future major adverse cardiac events risk, followed by PR and PE. Future studies should evaluate the possibility of ACS underlying cause-based optical coherence tomography-guided optimization.

Keywords: acute coronary syndrome; major adverse cardiovascular events; optical coherence tomography.

Figure 1. Flowchart of patient enrollment and prevalence of underlying causes of ACS.

A, Flowchart of patient enrollment; B, Representative OCT images of PR, PE, and CN; C, Prevalence of underlying causes of ACS. ACS indicates acute coronary syndrome; CN, calcified nodule; OCT, optical coherence tomography; PCI, percutaneous coronary intervention; PE, plaque erosion; and PR, plaque rupture.

Figure 2. Frequency of OCT‐based PCI strategy changes.

More than 1 strategy change could coexist in each individual patient. OCT indicates optical coherence tomography; and PCI, percutaneous coronary intervention.

Figure 3. Kaplan–Meier time‐to‐event curve for the cumulative MACE rate.

CN indicates calcified nodule; HR, hazard ratio; MACE, major adverse cardiac events; PE, plaque erosion; and PR, plaque rupture.

Figure 4. Unadjusted and adjusted hazard ratios for MACE.

A, Unadjusted hazard ratios for MACE; B, Adjusted hazard ratios for MACE. CN indicates calcified nodule; HR, hazard ratio; MACE, major adverse cardiac events; PE, plaque erosion; and PR, plaque rupture.