Improvement in identification of multivessel disease after acute myocardial infarction following stress-recovery analysis of ST depression in the heart rate domain during exercise

Abstract

The demonstration of extensive coronary artery disease (CAD) after acute myocardial infarction (AMI) has important prognostic implications. Exercise-induced ST segment depression is commonly used for detecting the presence of CAD and evaluating its extension. However, even though there have been many attempts to increase its diagnostic yield, the accuracy of the electrocardiographic signal for identifying multivessel disease (MVD) is relatively low, particularly in post-MI patients. The aim of this study was to evaluate the ability of a simple index, combining information on the amount and kinetics of ST depression in the heart rate domain during exercise and recovery, to identify MVD after AMI. Seventy patients (mean age 53.4 years) underwent a bicycle, symptom-limited exercise stress test and coronary angiography 2-3 weeks and 6 weeks respectively, after uncomplicated AMI while cardioactive therapy was discontinued. After obtaining a computer-derived measurement of ST levels based on incremental averaging of normal complexes, the area subtended to baseline and limited by the ST trend against heart rate during both exercise (A1) and recovery (A2) was calculated. The difference (A1-A2) was defined as the 'Stress-Recovery Index' (SRI) and dichotomized, by means of receiver-operating characteristics curve analysis, at 5 mm x beats.min-1 to define an increased risk of MVD. The SRI of patients with MVD was significantly lower than that of patients with single vessel disease. The sensitivity of SRI < -5 mm x beats.min-1 (65%) for predicting MVD was significantly higher than that obtained by other conventional parameters, without appreciable loss of specificity (81%).(ABSTRACT TRUNCATED AT 250 WORDS)

Exercise Electrocardiogram Testing

“…88 A recent evaluation by Svensburgh et al 90 has addressed the effect on test performance of the exact range of heart rates included in the rate-recovery area calculation, noting that a large percentage of the loop needs to be considered to optimize diagnosis, especially in women. Bigi et al 96 examined the entire rate-recovery loop by defining a stress-recovery index as the difference in areas under the full exercise and recovery phase ST/HR plots. The stressrecovery index has been found to be more accurate than other standard ST segment-and heart rate-adjusted test methods for the identification of anatomically extensive disease after myocardial infarction, 96 for the prediction of mortality after myocardial infarction, 97 and for the prediction of all-cause mortality in hypertensive patients with chest pain.…”

“…Bigi et al 96 examined the entire rate-recovery loop by defining a stress-recovery index as the difference in areas under the full exercise and recovery phase ST/HR plots. The stressrecovery index has been found to be more accurate than other standard ST segment-and heart rate-adjusted test methods for the identification of anatomically extensive disease after myocardial infarction, 96 for the prediction of mortality after myocardial infarction, 97 and for the prediction of all-cause mortality in hypertensive patients with chest pain. 98 Thus, combination of exercise and recovery phase STsegment data as an area of the ST/HR loop appears to be the most accurate and predictive of the current heart rateadjusted methods in routine exercise testing.…”

Exercise electrocardiography detection of coronary artery disease by ST-segment depression/heart rate hysteresis in women: The Finnish Cardiovascular Study

“…Other researchers have also shown ST/HR analysis integrating exercise and recovery to improve the diagnostic capacity of exercise ECG [15][16][17][18]. However, the majority of patients in the previous studies have been men, and hitherto the diagnostic performance of ST/HR hysteresis in women has been unknown.…”

The Stress-Recovery Index for the risk stratification of women with typical chest pain

“…Details on SRI determination have been extensively described elsewhere [7,10]. Briefly, computer-calculated STsegment amplitudes were obtained every 12 s during exercise and up to five minutes during recovery.…”

“…In addition, due to the limited value of exercise ECG, interest has grown in the use of more expensive and less generally available imaging techniques for assessing CAD in the female population [6]. The Stress-Recovery Index (SRI) has been proposed to improve the diagnostic accuracy of exercise ECG [7]. In addition, it has been shown to provide prognostic information outperforming that of standard ST-segment depression criteria in a variety of clinical settings [8][9][10][11].…”