Simple cardiovascular reflex test during hospitalization due to myocardial infarction predicts sudden but not non-sudden cardiac death during 2 years follow up

Background. Prognostic significance of heart rate (HIR) response to easy to perform provocative maneuvers such as Valsalva maneuver and deep breath recuires further elucidation. Methods. Valsalva maneuver with calculation of Valsalva ratio (VR) and deep breath test with calculation of difference between average maximal and minimal HR during first minute of test (HRD) were performed in 210 patients on days 4-11 of myocardial infarction (MI). This analysis included data from 188 patients (68,1% men, age 34-75 years, 93.6% on beta-blockers during test). Results. During period of follow up for 2.1 +/- 0.8 years there were 9 sudden (SD) and 13 non-sudden (non-SD) cardiac deaths. ROC-analysis allowed to determine optimal prognostic values of VR (<1.13) and HRD (<3.36) for SD. For non-SD these values could not be determined. According to univariate logistic regression analysis predictors of SD were as follows: VR<1.13 (OR 7.8, 95% Cl 1.6-39.0, p=0.012), HRD <3.36 (OR 4.3, 95%CI 1.1-16.9, p=0.034), history of MI, ventricular fibrillation during first 24 h of MI, clinical heart failure (NYHA class II-III) on the day of tests. At multivariate analysis independent predictors of SD were history of MI (OR 8.3, 95% CI 1.5-46.2, p=0.015), ventricular fibrillation during first 24 h of MI (OR 72.3, 95% CI 5.1-1032.9, p=0.002) and VR <1.13 (OR 7.36, 95% CI 1.3-41.7, p=0.024). Univariate predictors of non-SD included history of MI, history of heart failure, HR on admission and postinfarction angina. HR on admission >= 91 bpm was the single independent predictor of non-SD (OR 3.8, 95% Cl 1.1-13.0, p=0.034). Conclusion. Valsalva ratio <1.13 on days 4-11 of MI in patients with sinus rhythm and without severe heart failure was associated with high risk of SD but not of non-SD during 2 years of follow up.