The relationship between 1-year mortality and infarct location in patients with non-Q wave myocardial infarction

Implications of myocardial reperfusion on survival in women versus men with acute myocardial infarction undergoing primary coronary intervention

We evaluated the effects of myocardial perfusion after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) on gender-based mortality rates. Research has demonstrated a gender-specific response of cardiomyocytes to ischemia and a potential increase in myocardial salvage in women compared with men. Myocardial blush grade (MBG), an angiographic surrogate of myocardial perfusion, is an independent predictor of early and late survival after AMI. Whether the incidence and prognosis of myocardial perfusion differs according to gender among patients with AMI undergoing PCI is unknown. MBG and short- and long-term mortality were evaluated in 1,301 patients (male = 935; female = 366) with AMI randomized to primary angioplasty ± abciximab versus stent ± abciximab. Following PCI, >96% of patients achieved final Thrombolysis In Myocardial Infarction 3 flow, of which MBG 2/3 was present in 58.3% of women versus 51.1% of men (p = 0.02). Worse MBG was an independent predictor of mortality in women at 30 days (7.4% for MBG 0/1 vs 2.4% for MBG 2/3, p = 0.04) and at 1-year (11.0% for MBG 0/1 vs 3.4% for MBG 2/3, p = 0.01); however, MBG was not associated with differences in mortality for men. In conclusion, impaired myocardial perfusion following PCI for AMI, indicated by worse MBG, is an independent predictor of early and late mortality in women but not in men. These findings imply an enhanced survival benefit from restoring myocardial perfusion for women compared with men during primary angioplasty and may have clinical implications for interventional strategies in women.

Mean platelet volume predicts left descending artery occlusion in patients with non-ST-elevation myocardial infarction

Platelets play an important role in atherothrombosis. As the most common site plaque occurs, left anterior descending artery (LAD) infarct location always associate with poor prognosis. We sought to assess whether mean platelet volume (MPV) could predict LAD infarct location and short-term clinical outcome. In this study, 190 consecutive patients with non-ST-elevation myocardial infarction (NSTEMI) were enrolled. Clinical, electrocardiography and laboratory characteristics were measured. All patients underwent coronary angiography examination and had definite culprit vessel during hospitalization. The results showed that MPV was smaller in patients with a LAD infarct location than that of left circumflex artery or right coronary artery (9.0 ± 1.5 versus 9.8 ± 1.6, p<0.001). Multivariate analysis also showed that MPV was the only independent factor to predict LAD infarct location [Odds ratio (OR)=0.65, 95% confidence interval (CI) 0.53-0.80, p<0.0001] in patients with NSTEMI. B-type natriuretic peptide and electrocardiography were unreliable predictive factors to locate culprit vessel. Receiver operating characteristic curve analysis showed MPV (area under the curve: 0.65, 95% CI 0.56-0.74, p<0.01) could reliably discriminate those patients with NSTEMI who had a major in-hospital event. Multivariate regression analyses also showed that MPV (OR=1.46, 95% CI 1.15-1.86, p<0.01) were predictors of major in-hospital events. In conclusion, MPV was the only factor independently associated with LAD infarct location in patients with non-ST-elevation myocardial infarction.

B-type natriuretic peptide as a predictor of anterior wall location in patients with non-ST-elevation myocardial infarction

OBJECTIVE

Involvement of the left ventricular anterior wall in ST-elevation myocardial infarction has a worse prognosis compared with other regions. In non-ST-elevation myocardial infarction, noninvasive methods of locating the ischemic myocardial territory have been limited. The objective of this report is therefore to determine what factors are predictive of the anterior location of the ischemic myocardial territory.

METHODS

This study included 170 patients with non-ST-elevation myocardial infarction. Clinical, echocardiographic, and laboratory characteristics, including B-type natriuretic peptide measured within 24 hours of hospitalization, and coronary angiographic features were analyzed.

RESULTS

The mean age was 64.5 ± 12.3 years, and 112 of the patients were male (66%). The median follow-up was 23 months. The territory involved, as determined from the angiogram, was divided into anterior [n = 80 (47%)] regions and inferior and lateral [n = 90 (53%)] regions. Multivariate analysis showed that B-type natriuretic peptide was the only independent predictor of an anterior wall infarct [OR = 3.70 (95% CI: 1.61 - 8.53); P = 0.002] in non-STelevation myocardial infarction patients. Multivariate analysis also showed that B-type natriuretic peptide was an independent predictor of in-hospital cardiac events during index admission [OR = 5.05 (95% CI: 1.49 - 17.12); P = 0.009] and of cardiac events occurring during follow-up [HR = 1.79 (95% CI: 1.05 - 3.04); P = 0.032].

CONCLUSIONS

B-type natriuretic peptide was the only factor independently associated with anterior wall involvement in non-ST-elevation myocardial infarction, and the peptide levels upon admission predicted in-hospital and subsequent cardiac events.

Risk stratification post-myocardial infarction: is early coronary angiography the more effective strategy?

The primary management strategy for the post-myocardial infarction patient continues to be controversial despite published guidelines. In part, this is the consequence of study designs that are not directly applicable to individual patients, but also to the rapidly changing pharmacological and mechanical device armamentarium that rapidly renders clinical trial results obsolete within a few years. This review attempts to highlight those areas where there is consensus as well as to explicate those situations where common clinical practice appears to be in conflict with accepted guidelines.

Early angiography versus conservative treatment in patients with non-ST elevation acute myocardial infarction: MITI Investigators. Myocardial Infarction Triage and Intervention

OBJECTIVES

To compare short- and long-term outcome after early invasive or conservative strategies in the treatment of non-ST segment elevation acute myocardial infarction (AMI).

BACKGROUND

It is uncertain whether or not there is benefit from emergent invasive diagnosis and treatment of AMI in patients without ST segment elevation on the admission electrocardiogram (ECG).

METHODS

In a cohort of 1,635 consecutive patients with AMI who presented to hospitals without ST segment elevation on their admission ECG, we compared treatments, hospital course and outcome in 308 patients who presented to hospitals whose initial strategy favored early angiography and appropriate intervention when indicated versus 1,327 similar patients who presented to hospitals that favor a more conservative initial approach.

RESULTS

At baseline, patients admitted to hospitals favoring an early invasive strategy were younger, more predominately Caucasian and had less comorbidity. Early coronary angiography occurred in 58.8% versus 8% (p < 0.001), and early angioplasty was performed in 44.8% versus 6.1% (p < 0.001) in the two different cohorts. Patients treated in hospitals favoring the early invasive strategy had a lower 30-day (5.5% vs. 9.5%, p = 0.026) and four-year mortality (20% vs. 37%, p < 0.001). Multivariate analysis showed a trend towards lower hospital mortality (OR = 0.56, 95% CI: 0.29 to 1.09) and a significant lower long-term mortality (hazard ratio = 0.61, 95% CI: 0.47 to 0.80) in patients admitted to hospitals favoring an early invasive strategy.

CONCLUSIONS

These data suggested that an early invasive strategy in patients with AMI and nondiagnostic ECG changes is associated with lower long-term mortality.

Comparison of short- and long-term prognosis in patients with anterior wall versus inferior or lateral wall non-Q-wave acute myocardial infarction. Secondary Prevention Reinfarction Israeli Nifedipine Trial (SPRINT) Study Group

We evaluated the early and long-term prognosis of patients with a first non-Q-wave acute myocardial infarction (AMI) in relation to infarct site. Among 4,314 patients with a first AMI, 610 (14%) had a non-Q-wave AMI. Of them, 248 patients with anterior wall AMI were compared with 327 patients with inferior/lateral AMI. Baseline clinical characteristics were similar in both groups except for higher mean age in the anterior wall group. In-hospital complications were more common among patients with anterior wall AMI than in the inferior/lateral group. Patients with anterior wall AMI also had higher rates of in-hospital (15%), 1-year (12%), and 5-year (36%) postdischarge mortality compared with the inferior/lateral infarction group (10%, 6%, and 22%, respectively). The 1-year cardiac event rate (recurrent AMI and cardiac death) was significantly higher among the anterior wall AMI group than the inferior/lateral AMI group (14.2% and 4.8% respectively, p = 0.001). After adjustment for age, gender, systemic hypertension, diabetes mellitus, prior angina, and treatment with various medications, an increased risk for 1-year (odds ratio 1.31, 95% confidence interval [CI] 0.62 to 2.78) and 5-year mortality (relative risk 1.29, 95% CI 0.90 to 1.85) was observed, but it did not reach statistical significance. Anterior wall AMI location emerged as a predictor for higher 1-year cardiac event rate (odds ratio 3.15, 95% CI 1.59 to 6.78). These findings suggest that AMI location is an important prognostic variable for risk stratification of patients with a first non-Q-wave AMI.

Prognostic significance of ST-T segment alterations in patients with non-Q wave myocardial infarction

OBJECTIVE

To determine whether, among patients with non-Q wave myocardial infarction, the characteristics of the segment ST-T shifts at presentation in the diagnostic electrocardiogram can identify those with more severe coronary artery disease and predict a poor clinical outcome.

DESIGN

Prospective controlled clinical trial.

SETTING

Primary referral medical centre.

PATIENTS

93 patients (mean (SD) 62.0 (7.5) years) were studied: 41 with non-Q wave myocardial infarction and T wave inversion and 52 with ST segment depression. Cardiac events and mortality rates were assessed over 42 months. Age, sex, risk factors, creatinine kinase MB isoenzyme peak, and left ventricular function were comparable.

RESULTS

31 patients with T wave inversion myocardial infarction (94.6%) had total occlusion of the infarct related artery, compared with 12 patients with ST segment depression myocardial infarction (26.7%) (P < 0.05). When compared with patients with T wave inversion, patients with ST segment depression had a higher incidence of cardiac events during the first month and in the 41 subsequent months: 9.6% and 30.8% v 0% (P < 0.01) and 9.8% (P < 0.02), respectively. For the same observation periods, the mortality rates in patients with T wave inversion were 4.9% and 7.3%, and in patients with ST segment depression they were 5.8% and 9.6%, respectively.

CONCLUSION

These data suggest that during a non-Q wave myocardial infarction the presence of ST segment depression is related to higher rates of short and long term cardiac events when compared with T wave inversion--possibly because of a higher incidence of residual stenosis of the infarct related artery.