[Effectiveness of the Palmaz Schatz stent in elderly patients with unstable angina: factors predictive of short-term and long-term events]

Abstract

Introduction: To evaluate clinical, procedural and therapeutical predictors of in- and out-hospital events in the elderly, we analyzed 69 consecutive patients (age: 74, range: 70-87) with unstable angina who successfully underwent Palmaz Schatz coronary stenting.

Methods: Between March 1991 and March 1994, after the stenting procedure, a cohort of 38 patients (AC) was treated with iv heparin for 48 hours, warfarin (dosage titrated on INR) and dipiridamole (75 mg tid) for 3 months, aspirin (325 mg a day) chronically; between April 1994 and April 1995, after 48 hours of iv heparin, a second cohort of 31 patients (NO AC) received subcutaneous low molecular weight heparin (4000 U a day) for a week, ticlopidine (250 bid) for 1 month, and aspirin (100 mg a day) chronically. NO AC patients showed, by protocol, a higher postdilatation pressure (14 +/- 2 vs 9 +/- 3 atm, p < 0.0001).

Results: The 2 cohorts of patients were similar with respect to baseline clinical and angiographic findings. A shorter hospital stay (5 +/- 2 vs 10 +/- 6 days, p < 0.0001) and a lower incidence of in-hospital events were seen in the NO AC group (3.2 vs 24%, p = 0.028), both by a reduction of ischaemic events (3.2 vs 10.5%, p = ns) and hemorrhagic events (0 vs 13.2%, p = 0.03). During a mean follow-up of 21 +/- 13 months, NO AC patients did not show a significant lower rate of out-hospital events (1 year event-free survival respectively 94.7% in NO AC cohort vs 85.7% in AC cohort, p = ns). At logistic regression model, anticoagulant therapy (OR 10.89, Cl 1.39-85.28, p < 0.05) and refractory angina (Braunwald C3) (OR 5.70, Cl 1.12-29.03, p < 0.05) were significantly related to the incidence of acute events, while refractory angina (OR 5.76, Cl 1.27-26.00, p = 0.02) and multivessel disease (OR 3.31, Cl 0.89-12.20, p = 0.07) to the occurrence of late cardiac events, particularly for a higher risk of non-target site new revascularizations. Stent implantation on saphenous vein graft was also associated to a higher risk of repeating a revascularization of non-treated sites (20 vs 4%, p = 0.021).

Conclusions: In elderly with unstable angina treated with Palmaz Schatz stenting, NO AC patients showed a significant reduction of in-hospital events without a subsequent higher risk of late events. In addition, refractory angina, multivessel disease and stent implantation on saphenous vein graft were the other main clinical variables predictive of out-hospital events particularly for higher risk of non-target site new revascularizations.