Which Coronary Lesions Are More Prone to Cause Acute Myocardial Infarction?

Abstract

BackgroundAccording to common belief, most myocardial infarctions (MIs) are due to the rupture of nonsevere, vulnerable plaques with < 70% obstruction. Data from recent trials challenge this belief, suggesting that the risk of coronary occlusion is, in fact, much higher after severe stenosis. The aim of this study was to investigate whether or not acute ST-elevation MIs result from high-grade stenoses by evaluating the presence of coronary collateral circulation (CCC).MethodsWe retrospectively included 207 consecutive patients who had undergone primary percutaneous coronary intervention for acute ST-elevation MI. Collateral blood flow distal to the culprit lesion was assessed by two investigators using the Rentrop scoring system.ResultsOut of the 207 patients included in the study, 153 (73.9%) had coronary collateral vessels (Rentrop 1-3). The Rentrop scores were 0, 1, 2, and 3 in 54 (26.1%), 50 (24.2%), 51 (24.6%), and 52 (25.1%) patients, respectively. Triglycerides, mean platelet volume (MPV), white cell (WBC) count, and neutrophil count were significantly lower in the group with good collateral vessels (p = 0.013, p = 0.002, p = 0.003, and p = 0.021, respectively).ConclusionMore than 70% of the patients with acute MI had CCC with Rentrop scores of 1-3 during primary coronary angiography. This shows that most cases of acute MI in our study originated from underlying high-grade stenoses, challenging the common believe. Higher serum triglycerides levels, greater MPV, and increased WBC and neutrophil counts were independently associated with impaired development of collateral vessels.

Mouse models of atherosclerosis and their suitability for the study of myocardial infarction

“…Atherosclerosis sufficient to cause stenosis and ischaemia gradually affects the entire structure of the coronary tree by stimulating the development of coronary collateral vessels, such that they are detected in up to ~ 70% of patients with acute MI [ 183 , 215 ]. This is important because residual blood flow carried by collaterals at the time of acute MI can limit infarct size.…”

Left Atrial Remodeling and short-Term Outcome in Patients Presenting with Non- ST Segment Elevation Myocardial Infarction

“…This comes in hand with Roth and Elkayam (13) , which stated that the vast majority of MI involves the anterior wall (78%) Roth and Elkayam (13) and Shahzad et al (14) , who proposed that the most common coronary artery affected is the left anterior descending (LAD) branch. The left anterior descending artery was the most common culprit artery (48.3%), followed by the right coronary artery (30.9%), and the circumflex artery (20.8%) in a study (15) .…”

Autopsy Cardiac Troponin I Plasma Levels Can Be Elevated in Myocardial Infarction Type 3

“…For the diagnosis of MI type 3, each decedent died suddenly and unexpectedly after a terminal and brief presentation with the typical signs and symptoms of myocardial ischemia/infarction 1 before a clinical diagnosis of MI was made. Autopsy revealed severe or significant coronary atherosclerosis 2–4 with at least 1 major coronary artery showing 75% to 100% focal, segmental, or diffuse luminal occlusion without intraluminal thrombosis, complicated plaque or plaque rupture, accompanied by histologic evidence of ischemic myocyte injury with multifocal myofibrillary waviness, myofibrillary cytoplasmic hypereosinophilia, and/or contraction band myofibrillary degeneration/necrosis without any neutrophilic infiltration. There was no gross myocardial evidence of acute or subacute MI at autopsy.…”