The Impact of Coronary Artery Calcium on Post-PCI Outcomes
- Researchers examined the impact of coronary artery calcium on post-PCI outcomes in patients with STEMI.
- All-cause mortality and incidence of MACE and STEMI were higher at follow-up in patients with moderate/severe coronary artery calcification.
During percutaneous coronary intervention (PCI), cardiologists often confront various patient-specific challenges that limit optimal angiographic outcomes. These challenges include lesion tortuosity, bifurcations, and calcification.1 The presence of coronary artery calcium (CAC), for instance, has been linked with poor prognosis following elective PCI for patients with ST-elevation myocardial infarction (STEMI), yet the research regarding the full impact of CAC following PCI is limited.
Researchers from the Brigham and Women’s Heart and Vascular Center, Harvard Medical School, Rabin Medical Center, and Tel Aviv University explored the full effect of CAC on post-procedural outcomes in STEMI patients following PCI, particularly all-cause mortality at 1 year.1 Additionally, researchers wanted to determine the 2-year post-procedural incidence of the following:
- Ischemia-driven target vessel revascularization (TVR): Revascularization involving the target vessel
- Major adverse cardiac events (MACE): Recurrent myocardial infarction (MI), ischemia-driven TVR, and composite of cardiac death
- Recurrent MI: Serum cardiac enzyme elevation twice the normal upper limit, chest discomfort indicative of acute coronary syndrome, and new occurrence of Q waves following index hospitalization
- Stent Thrombosis (ST): Thrombosis of previously implanted stent as evidenced by angiography and culprit coronary territory reinfarction
Researchers in this post hoc study examined data from a registry of patients (N=2143) treated with primary PCI. Pre-PCI coronary angiograms ascertained CAC severity; moderate CAC generally involved 1 side of the vascular wall and severe CAC involved both sides of the arterial wall.
Moderate/severe CAC patients were older, had chronic kidney disease, used statins more frequently, had a higher incidence of peripheral vascular disease, and were female. A somewhat surprising finding, however, was that patients in the minimal to no CAC group were more likely to smoke and have a family history of coronary artery disease.
All-cause mortality at 1 year and 24-month follow-up was notably higher in the moderate/severe CAC group (Figure 1). In regard to secondary endpoints, the incidence of MACE and STEMI were both higher in the moderate/severe CAC group. Recurrent MI, however, was not significantly different in the group experiencing minimal to no CAC. Ischemia-driven TVR was also similar among the two CAC groups at 24-month follow-up.
Up to 15% of patients in this registry-based study treated with PCI had 1 or more calcified coronary arteries. This report also noted higher incidences of residual stenoses, no-reflow, and slow-flow. Treating calcified lesions with PCI may result in procedure failure due to a number of factors, including the occurrence of vascular stiffness, and stent underexpansion.
Despite this study finding higher mortality in the moderate/severe CAC group, recent advancement of PCI techniques has enabled more favorable outcomes for STEMI patients with moderate to severe CAC. Angiography, for example, can help determine the presence and severity of arterial calcification, predicting long-term prognosis and assisting in developing a tailored treatment course.
- Vaduganathan M, Kornowski R, Qamar A, et al. One-Year Outcomes After Primary Percutaneous Coronary Intervention for ST-Segment Elevation Myocardial Infarction With Varying Quantities of Coronary Artery Calcium (from a 13-Year Registry). Am J Cardiol. 2016;118(8):1111-1116.