PRETREATMENT WITH INTRACORONARY DILTIAZEM REDUCES NON-Q-WAVE MYOCARDIAL-INFARCTION FOLLOWING DIRECTIONAL ATHERECTOMY

The Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) reported a greater risk of non-Q-wave myocardial infarction (MI) with directional atherectomy (DCA), although the specific mechanism was unc lear. To assess the possible role of microvascular spasm in creatinine phosphokinase (CPK) elevation (> 2x normal) following DCA, 193 consec utive patients were given intracoronary diltiazem (2-6 mg) prior to DC A. These patients were compared with a retrospective control group of 400 consecutive patients who underwent DCA without diltiazem (all 593 procedures performed by a single operator). The groups were similar wi th respect to age, gender, clinical presentation and lesion morphology . Comparative analysis revealed that clinical success and the need for emergency bypass surgery was similar for each cohort. For patients wh o received intracoronary diltiazem prior to DCA, there was a significa nt decrease in the incidence of non-Q-wave myocardial infarction (2.7 vs. 6.8%, p =.04) and abrupt closure (2.5 vs. 6.2%, p = 0.05). These f indings suggest that intracoronary diltiazem prior to DCA may result i n a significant decrease in the rate of abrupt closure and non-Q-wave MI. Adjunctive intracoronary diltiazem should be considered in patient s undergoing DCA.