VALUE OF DECELERATION CAPACITY AFTER MYOCARDIAL INFARCTION
Aim: To evaluate predictive value of deceleration capacity (DC) for sudden cardiac death (SCD) risk stratification in patients after myocardial infarction (MI).
Methods: Study group: 111 patients after MI occurred more then 60 days before inclusion (77 men; age 64.1±10.5 years). Control group: 60 comparable subjects without any cardiovascular diseases. All subjects had 24-hour ambulatory ECG monitoring with DC evaluation. Primary endpoint was SCD, secondary endpoint included all other cardiovascular deaths.
Results: At baseline DC values were significantly lower after MI then in healthy subjects (4.2 [2.2;6.0] vs. 6,0 [4.7;7.1], respectively, ð<0,001) and were not dependent on MI type. During 12 months of follow-up we registered 15 cases of SCD and 8 cases of non-sudden deaths from cardiovascular diseases (including 5 lethal MI and 3 lethal strokes). DC values were significantly lower in all subgroups of lethals in compare with survivals. ROC-analysis showed a high diagnostic value of this measure for all-cause and cardiovascular mortality (AUC 0.7 and 0.67, respectively), and for SCD (AUC 0.7). In all cases DC was characterized by relatively high sensitivity and specificity, as well as very high negative predictive value (98.1% for all-cause mortality and 92.9% for SCD). DC values below threshold (4.15 for all-cause mortality and 2.0 for SCD) resulted in a significant increase in risk of all-cause mortality (OR 4.96, 95% CI 1.69 to 14.57, ð=0.002) and SCD (OR 6.97, 95% CI 2.19 to 22.2, ð=0.001).
Conclusion: Deceleration capacity is a significant and reliable independent risk predictor for all-cause and cardiovascular mortality, and SCD in patients after MI, and is characterized by high sensitivity, specificity and negative predictive value.