Risk stratification of patients with non-Q wave myocardial infarction. The critical role of ST segment depression. The Diltiazem Reinfarction Study Research Group.

Abstract

One-year follow-up data on 515 patients who survived hospitalization with MB-creatine kinase-confirmed, acute non-Q wave myocardial infarction were analyzed for factors related to mortality (n=57) and late reinfarction (n=64). Twelve of 24 analyzed variables were significantly associated with mortality. Those factors, which were independently predictive of mortality by Cox regression analysis, were persistent ST depression (p=0.0009), a history of congestive heart failure (CHF) (p=0.0069), older age (p =0.0128), and ST elevation at hospital discharge (p=0.0173). In-hospital reinfarction achieved borderline significance (p=0.0512).Mortality during the follow-up period was 5.5% in patients with no ST depression, 10.1% in those with ST depression at baseline or discharge, and 22.2% in patients with ST depression at baseline and discharge (i.e., "persistent" ST depression). The age-adjusted risk of mortality for patients with persistent ST depression, discharge-ST elevation, and CHF was 13.99 times as high as was the risk for patients with no ST depression, no discharge-ST elevation, and no CHF. Of the 483 patients with complete electrocardiographic data at both baseline and discharge, 203 (42%) could be stratified into a high risk population with a risk ratio for l-year mortality more than sevenfold that of patients with no risk factors. Although persistent ST depression was significantly associated with several measures of structural left ventricular damage, the independent significance of ST depression persisted even after adjusting for these factors. The independent predictors of late reinfarction (persistent ST depression, p=0.0058; Killip class II or III, p=0.0106; and left ventricular hypertrophy, p=0.0470) permitted a similar risk stratification. We conclude that 1) easily identified clinical and electrocardiographic factors permit stratification of patients with non-Q wave infarction into high-risk subsets who may benefit from aggressive therapy; 2) ST depression is a highly significant and independent predictor of poor prognosis; and 3) the powerful predictive value of persistent ST depression suggests that non-Q wave myocardial infarction patients with this depression should be viewed as potentially high-risk patients who may be candidates for additional noninvasive testing or early coronary angiography. (Circulation 1989;80:1148-1158 S tratification of postmyocardial infarction (MI) patients into low-and high-risk subgroups is vitally important in the overall investigation and management of patients, both acutely and long term. Risk stratification is particularly important during the first year after acute MI, the period

2011 ACCF/AHA Focused Update Incorporated Into the ACC/AHA 2007 Guidelines for the Management of Patients With Unstable Angina/Non–ST-Elevation Myocardial Infarction

“…In a study of 515 survivors of hospitalization for NSTEMI, risk factors included persistent ST-segment depression, HF, advanced age, and ST-segment elevation at discharge. 682 Patients with all high-risk markers present had a 14-fold greater mortality rate than did patients with all markers absent. Elevated cardiac TnT levels have also been demonstrated to provide independent prognostic information for cardiac events at 1 to 2 years.…”

2012 ACCF/AHA Focused Update Incorporated Into the ACCF/AHA 2007 Guidelines for the Management of Patients With Unstable Angina/Non–ST-Elevation Myocardial Infarction

“…age, and ST-segment elevation at discharge. 788 Patients with all high-risk markers present had a 14-fold greater mortality rate than did patients with all markers absent. Elevated cardiac TnT levels have also been demonstrated to provide independent prognostic information for cardiac events at 1 to 2 years.…”

The Effect of Tirofiban on ST Segment Resolution in Patients With Non-ST Elevated Myocardial Infarction

“…19,20) Several publications highlighted the prognostic value of ST segment depression in acute coronary syndromes (ACS). 21) ST segment depression is considered as one of the most important predictors of recurrent angina pectoris, reinfarction, and death in ACS. 5) Nyman and colleagues reported that patients with unstable angina and NSTEMI having ST segment depression on baseline admission ECG were at highest risk for cardiac death, MI, and severe angina pectoris with a follow-up of one year.…”

“…No significant relation could be found between ST segment resolution and these 5 factors. A possible clinical benefit of the appearance of ST segment resolution at the 72 nd hour can be speculated using the findings of the PRISM-PLUS trial, [13][14][15][16][17][18][19][20][21][22] which reported better outcomes compared to PRISM study where the tirofiban infusion was maintained during 72 hours in ACS compared to 48 hours in PRISM. 23) Patients who have invasive procedures seem to gain the most benefit from GP IIb/IIIa inhibitor treatment.…”