Current issues of ACP Journal Club are published in Annals of Internal Medicine


Prognosis

Right ventricular infarction predicted in-hospital mortality and complications in patients with acute inferior myocardial infarction

ACP J Club. 1993 Sept-Oct;119:52. doi:10.7326/ACPJC-1993-119-2-052


Source Citation

Zehender M, Kasper W, Kauder E, et al. Right ventricular infarction as an independent predictor of prognosis after acute inferior myocardial infarction. N Engl J Med. 1993 Apr 8;328:981-8.


Abstract

Objective

To determine the prognostic significance of right ventricular infarction in patients with an acute inferior myocardial infarction (MI).

Design

Inception cohort followed for a mean of 37 months.

Setting

University hospital in Germany.

Patients

200 consecutive patients (mean age 62 y, 153 men) hospitalized for an acute inferior MI diagnosed by chest pain lasting > 30 minutes; ST-segment elevation of ≥ 0.1 mV in ≥ 2 of leads II, III, and aVF; and an increase in serum creatine kinase to > twice the normal value < 24 hours after admission. All patients were followed for at least 1 year.

Assessment of prognostic factors

Right ventricular infarction (defined as ST-segment elevation in lead V4R), age, gender, maximal increase in creatine kinase, blood pressure, history of MI, use of thrombolytic therapy, ventricular fibrillation before hospitalization, and cardiogenic shock were assessed at the time of hospital admission.

Main outcome measures

In-hospital mortality and major complications.

Main results

38 patients (19%) died, and 94 patients (47%) had major complications during hospitalization. 107 patients (54%) had ST-segment elevation in lead V4R. 33 patients (31%) with an ST-segment elevation in lead V4R died in the hospital compared with 5 patients (6%) without such an elevation (P < 0.001). Major in-hospital complications also occurred more frequently in patients with an ST-segment elevation in lead V4R(64% vs 28%, P < 0.001). Multivariate analysis showed that ST-segment elevation in V4R(relative risk [RR] 7.7, 95% CI 2.6 to 23.0); age > 70 years (RR 3.2, CI 1.1 to 9.1); cardiogenic shock at admission (RR 11.4, CI 3.5 to 37.3); and use of thrombolytic therapy (RR 0.3, CI 0.1 to 0.9) were independent predictors of in-hospital mortality. Only ST-segment elevation (RR 4.7, CI 2.4 to 9.0) and cardiogenic shock (RR 6.1, CI 1.8 to 20.4) were predictive of major in-hospital complications. The post-hospital course for survivors was similar for patients with an ST-segment elevation in lead V4R and for those without such an elevation.

Conclusions

Right ventricular involvement during acute inferior myocardial infarction was an independent predictor of in-hospital mortality and major complications. The post-hospital course of patients with right ventricular involvement was similar to that of patients without this condition.

Source of funding: Not stated.

For article reprint: Dr. M. Zehender, Innere Medizin III, Universitätsklinik Freiburg, Hugstetterstrasse 55, 78 Freiburg, Germany. FAX 49-761-270-3457 or 3250.


Commentary

The study by Zehender and colleagues has practical clinical application for prognostication in the acute phase of myocardial damage. The authors have shown that ST-segment elevation in the V4R lead had good diagnostic accuracy for determining right ventricular involvement in patients with inferior MIs. The authors have also determined, with a high degree of reliability, that ST-segment elevation in V4R (as opposed to no elevation) predicts a much higher in-hospital mortality and complication rate in patients with inferior MIs.

The methods are exemplary. This group of patients appears to have been sicker than most reported patients with inferior MIs, having a 19% mortality rate before hospital discharge. Whether the presence or absence of elevated jugular venous pressure in the context of the right ventricular infarct modifies the morbidity and mortality cannot be easily gleaned from this study. This information might be of additional clinical value.

The authors suggest that right precordial leads, especially V4R, should be routinely used on all patients with inferior MIs. Unfortunately, the results of this study would not necessarily steer the physician to new therapies but, by signaling higher-risk patients, might encourage staff to monitor these patients more vigilantly for abnormal heart rhythms or congestive heart failure. Future interventional MI trials should take into account this new prognostic variable.

One's appetite is whetted by the reported incidence of right ventricular involvement in 10% of anterior myocardial infarcts (1). Is the prognostic implication the same?

Dwight I. Peretz, MD
University of British ColumbiaVancouver, British Columbia, Canada


Reference

1. Setaro JF, Cabin HS. Right ventricular infarction. Cardiol Clin. 1992;1:69-90.