Routine angiographic surveillance for risk stratification in PCI-treated patients: fact or fiction?

Patients with restenosis after coronary artery stent implantation may present with recurrent ischaemia, stable angina, and acute coronary syndromes. Restenosis may also be asymptomatic (without ischaemia), detected only on repeat angiography. Previous studies have demonstrated that angiographic measures including both in-stent and in-segment late loss and percentage diameter stenosis are valid surrogates for subsequent target lesion revascularization (TLR). Cassese and co-workers now raise the issue of whether routine surveillance angiography and the detection of asymptomatic restenosis might have clinical utility. Specifically, employing a strategy of routine follow-up angiography at 6–8 months after stenting, the authors identified angiographic restenosis in 2643 (26.4%) of 10 004 patients. After adjustment for clinical differences between groups, restenosis was an independent predictor of subsequent 4-year mortality [hazard ratio (HR) 1.23, 95% confidence interval (CI) 1.03–1.46); P 1⁄4 0.02], even if patients were asymptomatic (HR 1.40, 95% CI 1.06–1.87; P 1⁄4 0.01). Should routine surveillance angiography be considered after coronary stent implantation to detect asymptomatic restenosis and trigger repeat revascularization on the basis of this provocative study? It is well known that routine follow-up angiography results in a marked increase in TLR procedures in otherwise asymptomatic patients. In this regard, the angiographic restenosis rate of 26.4% in the series reported by Cassese et al. is substantially higher than the typical 5–10% rates of clinically driven restenosis found in most studies. Although routine angiographic surveillance is frequently performed to compare the efficacy of different stent systems, no prospective randomized trials have been performed to examine whether restenosis detected at routine angiographic follow-up has prognostic utility. In this regard, a meta-analysis of studies comparing outcomes of non-randomized patients assigned either to routine angiographic follow-up or to clinical follow-up alone demonstrated that the strategy incorporating routine angiographic surveillance was associated with increased ‘oculostenotic’ TLR of intermediate lesions without affecting subsequent rates of cardiac death or myocardial infarction.