[Treatment of myocardial infarction by primary PTCA within 12 to 24 hours after onset of pain]

Abstract

Background and objective: The time elapsed until effective infarct vessel perfusion has been identified as an essential determinant of survival after acute myocardial infarction (MI). Significant mortality rate reduction has not been demonstrated for patients who received thrombolytic treatment more than 12 to 24 hours after MI. For this reason such patients have so far largely been denied reperfusion treatment and have thus been excluded from any potential benefit of an reopened infarct vessel. It was the aim of this study to assess the applicability and safety of achieving reperfusion by percutaneous transluminal coronary angioplasty (PTCA) without prior thrombolysis (primary PTCA) within 12 (> 12) to 24 (< or = 24) hours after onset of pain, taking into account early and late results in selected consecutive patients.

Patients and methods: The data were analysed retrospectively of 35 patients (29 men, 6 women; mean age 60 [49-78] years) who had been admitted and treated by primary PTCA for MI more than 12-24 hours after onset of pain, with persisting ECG changes and (or) continuing chest pain. Reperfusion rates, acute haemodynamic parameters, acute cardiac and noncardiac complications, 30-day mortality rate, 3-month angiographic results and late mortality rate were obtained after an average of 23 (4-36) months.

Results: Complete infarct vessel reperfusion was achieved in 30 patients (85.7%), the infarct vessel remaining occluded in five. The early measurement of mean left ventricular ejection fraction was 53% (8-76%). A small, conservatively managed pericardial effusion occurred in one patient due to coronary artery penetration. Three patients who were in cardiogenic shock on admission died (8.6% 30-day mortality rate). Nine cases of restenosis and two of re-occlusion of the infarct vessel were documented in 24 patients who were investigated invasively 3 months after the primary PTCA. One patient had sustained a nonfatal MI. During the follow-up period one patient died of a noncardiac cause.

Interpretation: In this selected group of patients who received treatment more than 12 to 24 hours after MI primary PTCA achieved a high rate of reperfusion, while early and late complications were rare. Using individualized criteria of patient selection, primary PTCA can accomplish recanalization. The question of prognostic advantage can only be answered by results in a larger and randomized cohort of patients.