Table 2.
Stress test results in all study subjects and divided in non-CAD and CAD50 subjects
| All subjects n=155 | Non-CAD n=114 | CAD50 n=41 | P-value | |
|---|---|---|---|---|
| Pretest probability, % ± SD | 37.0±25.2 | 28.1±19.5 | 61.7±22.8 | <0.0001 |
| Stress test performance | ||||
| Duration, minutes ± SD | 9.3±3.7 | 9.3±3.7 | 9.3±3.4 | NS |
| Maximum workload, METS ± SD | 8.4±2.9 | 8.9±3.0 | 7.2±1.9 | 0.001 |
| Peak HR, beats/minute ± SD | 149.3±22.1 | 152.6±22.0 | 140.1±19.9 | 0.002 |
| % of max predicted HR, % ± SD | 92.0±11.2 | 92.6±11.2 | 90.5±11.3 | NS |
| Subjects reaching 85% of max predicted HR, n (%) | 123 (79.4) | 93 (81.6) | 30 (73.2) | NS |
| Peak SBP, mmHg ± SD | 193.8±30.9 | 192.7±30.9 | 196.9±28.4 | NS |
| Reason for termination of test | ||||
| Exhaustion, n (%) | 104 (67.1) | 76 (66.7) | 28 (68.3) | NS |
| Angina, n (%) | 4 (2.6) | 0 (0) | 4 (9.8) | <0.001 |
| Muscular weakness, n (%) | 23 (14.8) | 18 (15.8) | 5 (12.2) | NS |
| Dyspnea, n (%) | 20 (12.9) | 17 (14.9) | 3 (7.3) | NS |
| Arrhythmia, n (%) | 4 (2.6) | 3 (2.6) | 1 (2.4) | NS |
| Angina | <0.0001 | |||
| No, n (%) | 127 (81.9) | 103 (90.4) | 24 (58.5) | |
| Nonlimiting, n (%) | 24 (15.5) | 11 (9.7) | 13 (31.7) | |
| Limiting, n (%) | 4 (2.6) | 0 (0.0) | 4 (9.8) | |
| ST depression (mV) | 0.10 | |||
| 0.0, n (%) | 114 (73.6) | 88 (77.2) | 26 (63.4) | |
| ≥1.0, n (%) | 41 (26.5) | 26 (22.8) | 15 (36.6) | |
| Conclusion of the ET | 0.04 | |||
| Conclusive negative ET, n (%) | 88 (56.1) | 71 (61.2) | 17 (41.5) | |
| Inconclusive ET, n (%) | 22 (14.2) | 16 (14.0) | 6 (14.6) | |
| Positive ET, n (%) | 45 (28.7) | 27 (23.3) | 18 (43.9) | |
| ET protocol used | <0.001 | |||
| 25 watts/25 watts/2 minutes, n (%) | 119 (76.8) | 79 (69.3) | 40 (97.6) | |
| 50 watts/50 watts/2 minutes, n (%) | 36 (23.2) | 35 (30.7) | 1 (2.4) | |
Notes: Data are presented as mean ± SD, or n (%). CAD50 refers to subjects with ≥50% coronary artery lumen diameter stenosis.
Abbreviations: CAD, coronary artery disease; SD, standard deviation; MET, metabolic equivalent; HR, heart rate; SBP, systolic blood pressure at rest; ET, exercise test.