Implications of Prodromal Angina Pectoris in Acute Myocardial Infarction

Abstract

SUMMARY I PC phenomenon first described by Murry (1986) as a protective mechanism that induced by brief episodes of ischemia and reperfusion and protects the heart against prolonged ischemic damage. The cardioprotection effect of IPC occurs in two phases the first immediate and lasts for 2-4 hours while the second window of protection occurs at least 24 hours following the initial sub lethal ischemic insult and has been shown to last up to 72 hours in certain species. Several studies have demonstrated the protective effect of PA in AMI implicating the role of IPC. Prodromal angina occurring shortly before the onset of infarction, but not previous angina itself, has a beneficial effect on long-term prognosis after infarction, suggesting a relation to ischemic preconditioning. This study was designed to evaluate the effect of pre-infarction angina in the clinical setting of acute myocardial infarction. The current study was conducted on 60 patients presented to Ain Shams University Hospital diagnosed with first acute myocardial infarction. They were randomized into 2 groups each group consists of 30 patients group included the preconditioned patients and another one control group which include the non-preconditioned patients. - All of them were treated with the standard medical therapy for acute myocardial infarction according to the decision of treating physician. - All patients were subjected to: a) Detailed history taking: 1- Age, sex, hypertension, DM, special habits of medical importance specially cigarette smoking, current drug treatment and family history. 2- Special interest was drawn to the detection of the preinfarction anginal attacks within the last 24 hours. Such anginal attacks were defined as typical chest pain episodes similar in character to chest pain at admission but persisting ≤ 20 minutes either at rest or on effort within 24 hours before the onset of AMI. 3- The preinfarction anginal attacks were considered the stimuli of preconditioning phenomenon. 4- The approximate time of the preinfarction anginal attacks in the preadmission period was recorded and The exact number of preinfarction angina attacks was reported and these patients of group 2 (preconditioned patients) were classified into four subgroups: • Subgroup AC (classic preconditioning): Patients who reported preinfarction angina within 12 hours prior to admission with acute myocardial infarction and one to four preinfarction anginal attacks. • Subgroup AD (classic preconditioning): Patients who reported preinfarction angina within 12 hours prior to admission with acute myocardial infarction and who reported five or more preinfarction anginal attacks. • Subgroup BC (delayed pre-conditioning): Patients who reported preinfarction angina within 13-24 hours prior to admission with acute myocardial infarction (second window of protection) and one to four preinfarction anginal attacks • Subgroup BD (delayed pre-conditioning): Patients who reported preinfarction angina within 13-24 hours prior to admission with acute myocardial infarction (second window of protection) and who reported five or more preinfarction anginal attacks. b) A standard 12 lead ECG was obtained every morning until discharge and at any typical anginal pain. c) Blood samples for measuring CPK and CKMB plasma level were taken. d) During hospitalization all patients underwent coronary angiography either urgent PCI or elective coronary angiography. e) Predischarge complete transthoracic echocardiography examination was performed