ABSTRACT
To assess the usefulness of the post-exercise [recovery] to the peak exercise systolic blood pressure ratio [RSBP/PSBP] in the diagnosis of coronary heart disease [CHD], 100 patients [94 M and 6 F, mean age 49 +/- 8.7 yrs] were examined by ECG exercise test and coronary angiography. The series was divided into 3 groups: group I [40 pts, mean age 51 +/- 6.8 yrs] symptomatizing by typical chest pain but depicting nonspecific ST-T changes in the resting ECG; group II[40 pts, mean age 51.5 +/- 7.8 yrs] either known to have CHD in the form of a previous documented myocardial infarction, or preliminarily presenting a very high index of suspicion of CHD in the form of typically ischaemic ST-T changes in the resting ECG; and group III [20 pts, mean age 44 +/- 7.2 yrs] presenting with atypical chest pain but without resting ECG changes whatsoever. In group I, coronary angiography displayed single vessel disease [I VD] in 24 pts [60%], two-vessel disease [2VD] in 13 pts [32.5%] and triple vessel disease [3VD] in 3 pts [7.5%]; in group II, 23 pts [57.5%] had 1VD, 15 pts[375%] had 2VD and 2 pts [5%] had 3VD, whereas all patients in group III were proven to have normal coronary arteries. The duration of exercise test was significantly longer in group III than in both groups I and II. Patients in group III achieved a significantly higher level of maximal SBP than those of groups I and II [p = 0.0104]. An abnormal RSBP/PESBP ratio was defined as recovery SBP to peak exercise SBP ratio > 1, 0.9 and 0.8 at 1, 2 and 3 minutes of recovery respectively. An abnormal ratio was disclosed by 35 pts [87.5%] of group 1, 37 pts [92.5%] of group II and 3 pts [15%] of group III. On the other hand, chest pain during exercise testing occurred in 26 pts [65%] of group I, 28 pts [70%] of group II and 6 pts [30%] of group III. Significant ST-T displacement during exercise testing was developed in 23 pts [57.5%] of group I, 26 pts [65%] of group II and 4 pts [20%] of group III [these ST-T alterations were only typically ischaemic in the first 2 groups]. The RSBP/PSBP ratio has successfully detected CHD with a sensitivity of 85%, specificity of 70%, positive predictive value of 90%, negative predictive value of 68% and diagnostic accuracy of 85%: The sensitivity of exercise-induced chest pain in detecting CHD was only 67% the specificity was 70% positive predictive value 90% negative predictive value 35% and diagnostic accuracy 68% whereas the sensitivity, specificity, positive predictive value negative predictive value and diagnostic accuracy of exercise induced ST changes in the detection of CHD were 61%, 70%, 90%, 34% and 65% respectively. For combined ST changes and chest pain the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 90%, 72%, 93.5%, 70% and 88% respectively. It is noteworthy that 85% of patients with 1VD, 88% of those with 2VD and 100% of those. with 3VD have displayed an abnormal RSBP/PSBP ratio. Thus, the RSBP/PSBP ratio supercedes either exercise-induced angina or ST changes in the sensitivity of detection of CHD. Nevertheless, the combination of exercise angina and ST changes is more sensitive than the RSBP/PSBP in detecting CHD. The ratio exhibited a diagnostic accuracy in identifying patients with CHD that is comparable to ST changes and chest pain. Moreover, the RSBE/PSBP correlated well with the severity of CHD. The ratio is not, however, meant to replace the classical hallmarks of myocardial ischaemia during ECG stress testing, it might be rather perceived as an adjunct to those classical time-honoured criteria