Status of the myocardium and infarct-related coronary artery in 19 necropsy patients with acute recanalization using pharmacologic (streptokinase, r-tissue plasminogen activator), mechanical (percutaneous transluminal coronary angioplasty) or combined types of reperfusion therapy

Abstract

In acute myocardial infarction, myocardial salvage is dependent on rapid restoration of blood flow. Pharmacologic (streptokinase, recombinant tissue-type plasminogen activator), mechanical (percutaneous transluminal coronary angioplasty, guide wire perforation) or combined forms of reperfusion therapy can accomplish this goal, but their effects on infarcted myocardium and vessel occlusion site have not been compared at necropsy. The heart of 19 necropsy patients who had received various forms of acute reperfusion therapy was studied: 14 had pharmacologic or combined forms of reperfusion therapy (13 streptokinase and 1 tissue-type plasminogen activator, including 4 with combined balloon angioplasty) and 5 had had purely mechanical (balloon angioplasty) reperfusion therapy. Reperfusion was initially clinically successful in all 19 patients with the average time from onset of symptoms to reperfusion being 3.7 hours. Necropsy observations separated the 19 patients into distinct subgroups based on changes in the myocardium and infarct-related coronary arteries. Of the 19 patients, 14 (74%) had hemorrhagic myocardial infarction and they all received pharmacologic or combined forms of reperfusion therapy. The remaining five patients (26%) had nonhemorrhagic (anemic) infarction and were treated with balloon angioplasty therapy alone. Increased luminal cross-sectional area was present in 8 of 9 patients with acute balloon angioplasty but severe coronary atherosclerotic plaque remained in 9 of 10 patients without acute balloon angioplasty. Severe hemorrhage surrounded angioplasty sites in all four patients who also received streptokinase or tissue-type plasminogen activator. Severe bleeding at the angioplasty site compromised the dilated coronary lumen in one patient. No patient with angioplasty alone had intraplaque bleeding. Thus, acute coronary balloon angioplasty reperfusion therapy alone appears to avoid the potentially adverse effects of myocardial and intraplaque hemorrhage while simultaneously increasing luminal cross-sectional area at the site of acute occlusion.

Acute Coronary Care in the Elderly, Part II

“…21,25,26 Myocardial edema, contraction band necrosis, and intramyocardial hemorrhage are commonly noted at autopsy in elderly hearts after fibrinolysis. 27 In 706 elderly STEMI patients (Ն75 years of age), free wall rupture occurred in 17.1% treated with fibrinolytic therapy versus 4.9% who received PCI and 7.9% who received no reperfusion. 20 Fibrinolytic therapy may have unique adverse myocardial effects in those of advanced age.…”

Systematic review of fibrinolytic-facilitated percutaneous coronary intervention: Potential benefits and future challenges

“…In contrast with the early phase, mortality and myocardial salvage are influenced by time-independent (or 'less dependent') effects of reperfusion therapy, collateral circulation, ischemic preconditioning and myocardial oxygen demand (41,48). Moreover, reperfusion therapy may be associated with adverse effects such as contraction band necrosis (caused by rapid influx of calcium into dying cells), reperfusion injury, intramural hemorrhage, iatrogenic coronary artery dissection and distal microvascular embolization (49,50). Administering fibrinolytic therapy less than 2 h after symptom onset, more readily accomplished in the prehospital setting, halts myocardial injury at the reversible stages.…”

Angioplasty Strategies in ST-Segment–Elevation Myocardial Infarction

“…22,23 By treating the underlying fissured plaque, primary PCI also reduces recurrent ischemia and reinfarction compared with both fibrin-specific and -nonspecific agents. 13 Moreover, reperfusion injury and hemorrhagic transformation of a bland infarction, which occurs after fibrinolytic therapy but rarely after primary PCI, 24,25 also may result in increased myonecrosis and the mechanical complications of transmural infarction. 26 Finally, despite exclusion of patients at high risk for major bleeding and neurological events in the randomized comparative trials, log-rank p for trend = 0.0003 2.8% Figure 2.…”