PTCA in Acute Myocardial Infarction
We treated 210 patients admitted to the cardiac catheterization laboratory by the mobile intensive care unit within 3 h of the onset of chest pain using primary PTCA alone (group I), or a combination of an intravenous thrombolytic agent and angioplasty (group II). The goal of the study was to determine whether there were differences in feasibility of PTCA and in angiographic success rates during the acute phase of infarction and at follow up. At initial angiography in group II36% of vessels were patent, compared to 17% in group I. PTCA was attempted in all cases but was performed more easily in patients with patent vessels. It was possible to perforate the occlusion with a guide wire and balloon catheter and to perform angioplasty in a high percentage of cases — 92% in group I and 94% in group II. TIMI perfusion grades 2 and 3 were achieved by angioplasty in 89% of patients in group I and 86% in group II. Angiographic results immediately after angioplasty and at follow-up angiography were less favorable when PTCA was combined with a thrombolytic agent than when angioplasty was the sole re- canalization technique. Patent vessels with perfusion grades 2 and 3 were found at follow-up angiography in 83% of patients in group I compared to 77% of patients in group II. However, mortality was significantly lower in group II with combined thrombolysis and angioplasty than in the group treated with PTCA alone — 7.6% compared to 11%. Approximately half of all cases of reocclusion, reinfarction, and death occurred within the first 5 days of the hospital phase in both groups.
Primary PTCA in acute myocardial infarction would seem to be associated with fewer complications than the combination of PTCA with thrombolysis. Since early thrombolytic intervention has been shown to preserve left ventricular function, PTCA should be reserved for treatment failures when a thrombolytic agent is administered in the acute phase of myocardial infarction. However, re- canalization will not be achieved in at least one-third of patients, depending on the plasminogen activator used. Therefore, angiographic studies should be performed in the setting of acute myocardial infarction whenever possible.
High-grade residual stenosis is found in the majority of patients undergoing successful coronary recanalization with thrombolytic agents. Reocclusion is therefore one of the major problems encountered after successful thrombolysis. It occurs in 15%–30% of cases and seems to be directly related to the degree of residual stenosis.
KeywordsAcute Myocardial Infarction Balloon Catheter Thrombolytic Agent Residual Stenosis Patent Vessel
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