Diagnostic usefulness of postexercise systolic blood pressure response for detection of coronary artery disease in patients with electrocardiographic left ventricular hypertrophy

SBP ratio in exercise stress testing: validation by perfusion imaging

AIMS

The 3-min SBP ratio (SBPR) was proposed to detect significant coronary artery disease (CAD), but its relationship with abnormalities detected by myocardial perfusion-gated single-photon emission computed tomography (SPECT) was never examined.

METHODS

In 156 consecutive patients submitted to resting and exercise gated SPECT for suspect CAD, perfusion scores, ejection fraction and transient ischemic dilatation (TID) were evaluated and compared with SBPR.

RESULTS

There were weak correlations between SBPR and summed stress score (ρ = 0.232, P < 0.004), and summed difference score (SDS) (ρ = 0.228, P < 0.004). According to receiver operating characteristic analysis, SBPR was poorly effective for identifying patients with inducible ischemia (SDS ≥ 2): area under curve = 0.64, (P < 0.002), sensitivity = 82%, specificity = 40%. No relationship was registered between SBPR and postexercise ejection fraction drop, and the relationship with TID was poor (ρ = 0.263, P < 0.001).

CONCLUSION

In patients submitted to gated SPECT for suspect CAD, SBPR appears poorly effective for the detection of significant CAD, and does not show any valuable relationship with exercise-induced functional abnormalities.

Using an abnormal increase in postexercise systolic blood pressure to diagnose coronary artery disease in gerontal patients

Data from 66 patients ≥ 60 years old with suspected coronary artery disease (CAD) were studied to determine the diagnostic value of an abnormal increase in postexercise systolic blood pressure (SBP) for detecting CAD in gerontal patients. Treadmill exercise testing (TET) and selective coronary angiography (CAG) were carried out and SBP was measured pre-TET and at each minute during a 6-min post-TET recovery phase. Abnormal increase in postexercise SBP was defined as a higher SBP compared with that measured earlier during the 6-min post-TET period. An abnormal increase of ≥ 7 mmHg in postexercise SBP had a statistically significantly better specificity, and also showed higher sensitivity and accuracy, than ST-segment depression ≥ 1 mV in identifying gerontal patients with CAD. The combination of ST-segment depression and abnormal SBP resulted in further improvement of the specificity for detecting CAD. It is concluded that measurement of abnormal increase in postexercise SBP may be a sensitive indicator of gerontal CAD.

Usefulness of paradoxical systolic blood pressure increase after exercise as a predictor of cardiovascular mortality

Exercise treadmill testing (ETT) is a well-accepted examination for patients with suspected coronary artery disease (CAD), and exercise induced ST-segment deviation is commonly used for CAD detection. However, recent evidence shows that systolic blood pressure (SBP) changes during and after exercise were associated with CAD severity, risk of acute myocardial infarction and stroke, new-onset hypertension, and even cardiovascular mortality. We retrospectively assessed 3,054 patients referred for ETT in 1996. Blood pressure and heart rate were recorded at rest, during peak exercise, and 1 and 3 min after exercise. SBP at 3 min of recovery equal to or higher than that at 1-min of recovery was defined as paradoxical SBP increase. These patients were categorized into 4 groups according to ETT ST-segment change and postexercise SBP change. After 10 years of follow-up, 346 patients (11%) died, with 129 (4%) dying from cardiovascular disease (CVD). Among the 4 groups, patients with ischemic ST-segment change and paradoxical SBP increase were associated with a higher risk for mortality, with odds ratios of 1.86 (95% confidence interval 1.31 to 2.65) for all-cause mortality and 3.18 (95% confidence interval 1.94 to 5.20) for CVD mortality, respectively. Patients with isolated paradoxical SBP increase still had a higher risk of CVD mortality (odds ratio 1.80, 95% confidence interval 1.70 to 3.04), even after controlling other cardiovascular risk factors. In subgroup analysis of 346 mortality subjects, patients with ischemic ST-segment change and paradoxical SBP increase would be more likely to die from CVD. In conclusion, compared with ischemic ST-segment change, paradoxical SBP increase after exercise is an important and significant predictor of CVD mortality.

Postexercise VO2 “Hump” phenomenon as an indicator for inducible myocardial ischemia in patients with acute anterior myocardial infarction

OBJECTIVES

At exercise testing with respiratory gas analysis in patients with inducible myocardial ischemia, we have occasionally observed abnormal transient oxygen uptake (VO2) components with a characteristic "Hump"-shaped morphology early after exercise, which may serve as an index for inducible ischemia. We examined this hypothesis in patients with anterior q-wave myocardial infarction in whom the accuracy to identify ischemia by exercise ECG is limited.

DESIGN

From patients with acute anterior q-wave infarction but without clinically overt heart failure who underwent pre-discharge exercise testing, we examined patients with (Group-I, n = 30) and without (Group-N, n = 29) inducible ischemia. To identify "Hump", postexercise VO2 (up to 4 min) standardized for peak VO2 was exponentially fitted with use of peak VO2 and VO2 of 90-240 s, yielding "expected VO2". "D-curve" was obtained by subtracting "expected VO2" from measured VO2.

RESULTS

Although exercise-induced ST depressions more frequently appeared in Group-I (27%) than in Group-N (3%, p < 0.05), the prevalence was low. D-curve peaked later (p < 0.01) and its value was greater (p < 0.05) in Group-I than in Group-N. When "Hump" was defined to be present if D-curve peaked > or =40 s and its peak value > or =15%, it was far more frequently found in Group-I (n = 17/30) than in Group-N (n = 1/29, p < 0.01). Thus, "Hump" could diagnose inducible ischemia with a sensitivity of 57% and a specificity of 97%.

CONCLUSIONS

Although not highly sensitive, postexercise VO2 "Hump" with its peak occurring around 60 s after exercise is a specific marker for inducible ischemia. The identification may be useful, particularly in patients with limited accuracy of exercise ECG such as those with q-wave anterior infarction.

Assessment of coronary artery disease in hemodialysis patients with delayed systolic blood pressure response after exercise testing

BACKGROUND

We evaluated usefulness of the postexercise systolic blood pressure (SBP) response for detecting coronary artery disease (CAD) in hemodialysis patients.

METHODS

A treadmill exercise testing was done, and the SBP response was measured in 44 hemodialysis patients (30 men, 14 women; age 41 to 81 years). The postexercise SBP response was defined as the ratio of SBP after 3 minutes of recovery to SBP at peak exercise.

RESULTS

The SBP ratio of the 25 subjects with coronary artery stenosis (1.01+/- 0.13) was significantly greater (p<0.01) than 19 subjects without coronary artery stenosis (0.83+/- 0.10). An SBP ratio greater than 0.92 identified CAD with higher sensitivity, specificity, and accuracy than did the conventional ST-segment depression criterion (76 vs. 56%, 90 vs. 53%, and 82 vs. 55%, respectively).

CONCLUSION

Determination of the SBP ratio is a clinically useful, noninvasive method for accurately detecting CAD in hemodialysis patients.

Is systolic blood pressure recovery after exercise a predictor of mortality?

BACKGROUND

An attenuated systolic blood pressure recovery after exercise has been associated with the severity of atherosclerotic heart disease.

METHODS

For 6 years, we observed 12,379 patients who underwent symptom-limited exercise testing. We excluded patients receiving antihypertensive medication and patients with valvular disease, emphysema, end-stage renal disease, heart failure, left ventricular systolic dysfunction, and atrial fibrillation. Blood pressure recovery ratio was defined as the ratio of systolic blood pressure at 3 minutes into recovery to systolic blood pressure at peak exercise; this has been shown to correlate with angiographic severity of coronary disease.

RESULTS

The blood pressure recovery ratios ranged from 0.36 to 1.62, with values for increasing quartiles of 0.72 +/- 0.05, 0.82 +/- 0.02, 0.88 +/- 0.02, and 0.99 +/- 0.07. During follow-up, there were 430 deaths (3%). Five-year Kaplan Meier survival rates were 0.975, 0.974, 0.969, and 0.966 in quartiles 1 to 4, respectively. Compared with patients in the lowest quartile of blood pressure recovery ratio, patients in the highest quartile were at somewhat increased risk (hazard ratio, 1.71; 95% CI, 1.31-2.24; P <.001). However, after adjusting for age, sex, body mass index, resting heart rate and blood pressure, peak systolic blood pressure, heart rate recovery, exercise chronotropic response, cardiac history, and standard risk factors, this association was no longer present (adjusted hazard ratio, 1.05; 95% CI, 0.8-1.38; P =.74).

CONCLUSIONS

In this low-risk population, abnormal systolic blood pressure recovery after exercise was not independently predictive of mortality after correcting for differences in baseline and exercise characteristics.

Diagnostic usefulness of the post-exercise systolic blood pressure response for the detection of coronary artery disease in patients with diabetes mellitus

Patients with diabetes mellitus (DM) often have a positive result on exercise testing despite a normal coronary arteriogram, which indicates that exercise-induced ST depression is not always an accurate indicator of the presence of coronary artery disease (CAD) in such patients. The present study evaluated the usefulness of the post-exercise systolic blood pressure (SBP) response for the detection of CAD in 47 consecutive patients with DM. Significant stenotic lesions were detected by angiography in 25 patients; 18 of these had true positive (TP) exercise testing results, and 7 had false negative (FN) results. No significant stenotic lesions were detected in the remaining 22 patients and of these 10 had true negative (TN) exercise testing results, and 12 had false positive (FP) results. The SBP ratio (SBP after 3 min of recovery divided by the SBP at peak exercise) was significantly higher in patients with coronary stenoses than in those without. Analysis of the relative cumulative frequency revealed that a SBP ratio greater than 0.87 was associated with significant stenoses. The sensitivity, specificity, and accuracy of ST change combined with a SBP ratio greater than 0.87 for detecting stenoses in patients with DM were 68%, 82%, and 74%, respectively. These results suggest that calculating the SBP ratio, in combination with monitoring for ST depression, improves the accuracy of treadmill exercise testing for the detection of CAD in patients with DM.

Delayed systolic blood pressure recovery after graded exercise: an independent correlate of angiographic coronary disease

OBJECTIVE

This study was performed to determine whether a delayed decline in systolic blood pressure (SBP) after graded exercise is an independent correlate of angiographic coronary disease.

BACKGROUND

The predictive importance of the rate of SBP decline after exercise relative to blood pressure changes during exercise has not been well explored.

METHODS

Among adults who underwent symptom-limited exercise treadmill testing and who underwent coronary angiography within 90 days, a delayed decline in SBP during recovery was defined as a ratio of SBPs at 3 min of recovery to SBP at 1 min of recovery >1.0. Severe angiographic coronary artery disease was defined as left main disease, three-vessel disease or two-vessel disease with involvement of the proximal left anterior descending artery.

RESULTS

There were 493 subjects eligible for analyses (age 59 +/- 11 years, 78% male). Severe angiographic coronary disease was noted in 102 (21%). There were associations noted between a delayed decline in SBP during recovery and severe angiographic coronary disease (34% vs. 17%, odds ratio [OR] 2.59, confidence interval [CI] 1.58 to 4.25, p = 0.001). In multivariate logistic regression analyses adjusting for SBP changes during exercise and other potential confounders, a delayed decline in SBP during recovery remained predictive of severe angiographic coronary disease (adjusted OR 2.22, 95% CI 1.27 to 3.87, p = 0.005).

CONCLUSIONS

A delayed decline in SBP during recovery is associated with a greater likelihood of severe angiographic coronary disease even after accounting for the change in SBP during exercise.