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 unclear. To assess the possible role of microvascular spasm in creatinine phosphokinase (CPK) elevation (> 2x normal) following DCA, 193 consecutive patients were given intracoronary diltiazem (2-6 mg) prior to DCA. 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 with 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 who received intracoronary diltiazem prior to DCA, there was a significant 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 findings suggest that intracoronary diltiazem prior to DCA may result in a significant decrease in the rate of abrupt closure and non-Q-wave MI. Adjunctive intracoronary diltiazem should be considered in patients undergoing DCA.