Objectives: We sought to determine whether the stringent stress test criteria for crossover to cardiac catheterization in the conservative arm of the Fast Revascularization During Instability in Coronary Artery Disease (FRISC-II) trial subjected this strategy to a disadvantage by failing to identify patients with surgical coronary artery disease (CAD).
Background: In FRISC-II, an invasive strategy provided superior outcomes compared with a conservative strategy for patients with acute coronary syndromes. However, compared with the stress test criteria for crossover to catheterization in the Veterans Affairs Non-Q-Wave Infarction Strategies in Hospital (VANQWISH) trial, the FRISC-II criteria were more restrictive and did not use nuclear imaging or pharmacologic stress testing.
Methods: We analyzed the conservative arm of VANQWISH to identify the prevalence of surgical CAD in those patients who met the VANQWISH, but not FRISC-II, criteria for catheterization.
Results: Of 385 VANQWISH patients, 90 (23%) met the FRISC-II criteria for catheterization. Another 98 patients (25%) met only VANQWISH stress test criteria (60 patients by exercise and 38 by pharmacologic nuclear stress testing). Among subjects who underwent predischarge angiography, those meeting only VANQWISH stress test criteria had a high prevalence of surgical CAD (51%), comparable to patients who met FRISC-II criteria (54%, p = 0.805).
Conclusions: The overly stringent risk stratification protocol for conservative-arm patients in FRISC-II could have failed to identify almost as many patients with surgical CAD as it identified. A lower threshold for catheterization in the FRISC-II conservative patients might have improved their outcomes and therefore diminished the putative benefit of an invasive strategy.