Complex PCI is associated with higher risks of myocardial infarction, bleeding, and death compared to non-complex PCI in revascularization patients.

This systematic review and meta-analysis examined the safety and efficacy profiles of complex versus non-complex percutaneous coronary intervention (PCI) in patients undergoing myocardial revascularization. The study pooled data from multiple sources to assess a total population of 290,039 patients. The primary objective was to determine if the procedural complexity of PCI influences the risk of adverse cardiovascular events, specifically myocardial infarction and major bleeding, while also evaluating mortality and other secondary endpoints. The analysis utilized adjusted hazard ratios to account for potential confounding variables inherent in observational data.

The intervention of interest was defined as complex PCI, which typically involves high-risk anatomical features such as bifurcations, long lesions, or chronic total occlusions, compared to non-complex PCI procedures. The primary composite outcome included myocardial infarction and major bleeding. Secondary outcomes encompassed all-cause death, cardiovascular death, stent thrombosis, target lesion or vessel revascularization, and stroke. The follow-up duration varied across the included studies, but the meta-analysis provided pooled estimates for these endpoints.

Regarding the primary outcomes, the meta-analysis demonstrated a higher risk of myocardial infarction in the complex PCI group with an adjusted hazard ratio of 1.71 (95% CrI: 1.49-1.96). Similarly, major bleeding events were more frequent in the complex PCI cohort, showing an adjusted hazard ratio of 1.24 (95% CrI: 1.14-1.35). These results indicate a substantial increase in the likelihood of these specific adverse events when complex procedures are performed.

Mortality outcomes also favored the non-complex PCI group in terms of risk reduction. All-cause death occurred with an adjusted hazard ratio of 1.21 (95% CrI: 1.12-1.32) for complex PCI. Cardiovascular death showed a similar trend with an adjusted hazard ratio of 1.29 (95% CrI: 1.15-1.46). Furthermore, the risk of stent thrombosis was notably elevated in the complex PCI group, with an adjusted hazard ratio of 1.76 (95% CrI: 1.49-2.14).

Additional secondary outcomes revealed further differences in procedural complexity. The risk of target lesion or vessel revascularization was higher for complex PCI, with an adjusted hazard ratio of 1.99 (95% CrI: 1.58-2.50). Stroke risk was also elevated, though with lower certainty, showing an adjusted hazard ratio of 1.21 (95% CrI: 1.03-1.42). Safety analysis highlighted major bleeding as a key adverse event of concern, with no specific data reported on discontinuations or tolerability in the provided dataset.

The certainty of evidence was assessed as moderate to high for most outcomes, including myocardial infarction, bleeding, and mortality. However, the certainty for stroke was rated as low. These findings must be understood within the context of an association between complex PCI and event risk, rather than a direct causal link solely attributable to the procedural technique. The elevated risks likely reflect the underlying severity of coronary artery disease in patients requiring complex interventions, alongside potential procedural challenges.

Clinical implications suggest that physicians should be aware that complex PCI procedures are inherently linked to higher risks of adverse events compared to simpler procedures. This does not necessarily mean the procedure should be avoided, but rather that patients undergoing complex PCI require heightened vigilance and potentially more intensive post-procedural monitoring. Questions remain regarding whether specific procedural modifications or adjunctive therapies can mitigate these elevated risks. Future research should aim to clarify the causal mechanisms driving these associations and identify strategies to improve outcomes in high-risk PCI populations.