Adjusment of Heart Rate and Double-product to ST -segment Level, -index, and -integral in Exercise Testing

The aim of this study was to determine the performance of the methods devised by adjustment of heart rate (HR) and double-product (DP) changes to ST -segment level, ST -segment index, and STsegment integral changes during exercise testing and to find if any method had a test performanc.e, comparable to or superior than the standard method (using only ST-segment depression criteria). For this purpose, the best three methods in regard to the test performance were determined and compared to that of the standard method. One-lıundred and seven patients (33 female, 74 male, age 54±9,2) who underwent coronary angiography were enrolled in the study. Exercise tests were performed with ST/HR slope protocol within 1 O day s after coronary angiography. Adjustments of ST-segment level, -index, and -integral to HR and DP were made both with linear regression basis and simple adjustment method that is the ratio of ST-segment levels, -index, or -integral change to the HR or DP change during exercise testing. Coronary angiograms and exercise tests were assessed in a double-blind manner, and intraohserver variability for the assessment of coronary angiography was determined. Coronary angiograms were assessed by perfusion scoring with the Gensini scoring method. When all methods of the study were compared with their corresponding areas under receiver-operating curves; methods with linear-regression-based adjustments of ST-segment level to HR (ST-lev/HR slope), ST segment integral to HR (ST-int/HR slope); and the method with simple adjustment of the ST-segment level to HR (ST-lev/HR index) had signifıcantly superior test performance than the other methods. Sensitivities and specifıcities of these three methods were: 86%, 66%, 65%; 83%, 63%, respectively (all p<0.05). No signifıcant differences existed in performance among these three methods (ST lev/HR slope vs ST int/HR slope, p=0.097; ST lev/HR slope ve ST lev/HR index, p=0.074). When correlations of index or slope values of each patient were tested with their corresponding perfusion scores derived from the Gensini method, signifıcant correlations prevailed between them (r for STlev/ HR slope vs Gensini perfusion scores was 0.65, p