1-Year Outcomes of DEFINE PCI Trial

Quick Takes

  • Despite angiographically successful PCI, residual post-PCI ischemia as assessed by iFR was common, occurring in 24% of patients.
  • Achieving post-PCI iFR ≥0.95 was associated with a lower composite rate of cardiac death, spontaneous MI, or clinically driven TVR during 1 year of follow-up.
  • These data suggest that the use of intracoronary physiology during PCI may improve clinical outcomes not only by selection of appropriate lesions for PCI but also by potentially achieving optimal postprocedural results.

Study Questions:

What is the post–percutaneous coronary intervention (PCI) target value of instantaneous wave-free ratio (iFR) that would best discriminate clinical events at 1 year in the DEFINE PCI (Physiologic Assessment of Coronary Stenosis Following PCI) study?

Methods:

The investigators conducted a prospective, single-arm, blinded, multicenter study (DEFINE PCI) to assess the relationship between distal vessel iFR and iFR pull back and the distribution of physiologically significant coronary stenoses after successful PCI, as assessed by quantitative coronary angiography. Blinded iFR pull back was performed after successful stent implantation in 500 patients. The primary endpoint was the rate of residual ischemia, defined as iFR ≤0.89, after operator-assessed angiographically successful PCI. Secondary endpoints included clinical events at 1 year and change in Seattle Angina Questionnaire angina frequency (SAQ-AF) score during follow-up. Analysis of covariance was fitted using the Bayesian method, which directly estimates the probability distribution of the optimal post-PCI iFR effect with posterior means and 95% posterior density intervals.

Results:

As previously reported, 24.0% of patients had residual ischemia (iFR ≤0.89) after successful PCI, with 81.6% of cases attributable to angiographically unapparent focal lesions. Post-PCI iFR ≥0.95 (present in 182 cases [39%]) was associated with a significant reduction in the composite of cardiac death, spontaneous myocardial infarction (MI), or clinically driven target vessel revascularization (TVR) compared with post-PCI iFR <0.95 (1.8% vs 5.7%; p = 0.04). Baseline SAQ-AF score was 73.3 ± 22.8. For highly symptomatic patients (baseline SAQ-AF score ≤60), SAQ-AF score increased by ≥10 points more frequently in patients with versus without post-PCI iFR ≥0.95 (100.0% vs 88.5%; p = 0.01).

Conclusions:

The authors concluded that achieving post-PCI iFR ≥0.95 was also associated with improved 1-year event-free survival.

Perspective:

This study reports that despite angiographically successful PCI, residual post-PCI ischemia as assessed by iFR was common, occurring in 24% of patients. At 1-year follow-up, post-PCI iFR ≥0.95 compared with <0.95 was associated with diminished anginal symptoms at 12 months, especially in patients with significant angina at baseline. Furthermore, achieving post-PCI iFR ≥0.95 was associated with a lower composite rate of cardiac death, spontaneous MI, or clinically driven TVR during 1 year of follow-up. These data suggest that the use of intracoronary physiology during PCI may improve clinical outcomes not only by selection of appropriate lesions for PCI but also by potentially achieving an optimal postprocedural result. Given the small sample size and relatively short follow-up, additional longer-term prospectively driven studies are needed to confirm the value of post-revascularization physiology.

Keywords: Angina Pectoris, Coronary Angiography, Coronary Stenosis, Fractional Flow Reserve, Myocardial, Myocardial Infarction, Myocardial Ischemia, Myocardial Revascularization, Percutaneous Coronary Intervention, Physiology, Secondary Prevention, Stents, Survival


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