Study Finds That In-Stent Restenosis is Linked More to Patient Factors Than to Stent Type

December 2, 2014—Marco A. Magalhaes, MD, et al published findings from an investigation of clinical presentation of coronary in-stent restenosis (ISR) across three generations of stents. The study is available online ahead of print in Circulation: Cardiovascular Interventions.

The investigation’s background was that clinical presentation of bare-metal stent (BMS) ISR in patients undergoing target lesion revascularization (TLR) is well characterized and negatively affects outcomes, whereas the presentation and outcomes of first- and second-generation drug-eluting stents (DES) remains under-reported.

The investigators, led by Ron Waksman, MD, of MedStar Washington Hospital in Washington, DC, concluded that clinical presentation of ISR is similar irrespective of stent type and that myocardial infarction (MI) as ISR presentation seems to be associated with patient and not device-related factors. Additionally, acute coronary syndrome (ACS) as ISR presentation has an independent effect on major adverse cardiac events, suggesting that ISR remains a hazard and should be minimized.

As summarized in Circulation: Cardiovascular Interventions, the study included 909 patients (1,077 ISR lesions) distributed as follows: BMS (n = 388), first-generation DES (n = 425), and second-generation DES (n = 96), categorized into ACS or non-ACS presentation mode at the time of first TLR. ACS was further classified as MI and unstable angina.

The investigators reported that for BMS, first-generation DES, and second-generation DES, ACS was the clinical presentation in 67.8%, 71%, and 66.7% of patients, respectively (P = .47). MI occurred in 10.6%, 10.1%, and 5.2% of patients, respectively (P = .273).

The correlates for MI as ISR presentation were current smokers (odds ratio [OR], 3.02; 95% confidence interval [CI], 1.78–5.13; P < .001), and chronic renal failure (OR, 2.73; 95% CI, 1.6–4.7; P < .001), with a protective trend for the second-generation DES ISR (OR, 0.35; 95% CI, 0.12–1.03; P = .06).

ACS presentations had an independent effect on major adverse cardiac events (death, MI, and re-TLR) at 6 months (MI vs non-ACS: adjusted hazard ratio, 4.06; 95% CI, 1.84–8.94; P < .001; unstable angina versus non-ACS: adjusted hazard ratio, 1.98; 95% CI, 1.01–3.87; P =.046), reported the investigators in Circulation: Cardiovascular Interventions.