Hypertensive response with exercise does not increase the prevalence of abnormal Tc-99m SPECT stress perfusion images

An exaggerated increase in blood pressure with exercise does not predict mortality or severe cardiovascular events in women referred for exercise echocardiography for clinical reasons

BACKGROUND AND OBJECTIVES

The association between an exaggerated systolic blood pressure increase with exercise (EBPIE) and the probability of cardiovascular events is controversial and poorly studied in the female population. Our aim was to determine the possible association between EBPIE on one hand and mortality and cardiovascular events on the other in women referred for exercise echocardiography due to known or suspected coronary artery disease.

PATIENTS AND METHODS

A total of 3942 women with known or suspected coronary artery disease underwent exercise echocardiography. We defined EBPIE as a ≥70mm Hg increase in systolic blood pressure with exercise. The study endpoints were overall and cardiac mortality, acute myocardial infarction (MI), stroke and coronary revascularisation procedures.

RESULTS

A total of 332 women developed EBPIE during the test. During the follow-up, 458 deaths (162 of cardiac origin), 212 MIs, 89 strokes and 345 coronary revascularisation procedures were recorded. The annual rates of overall and cardiac mortality were lower in the patient subgroup with EBPIE (0.15% vs. 2.3%, P=.02 and 0.01% vs. 0.2%, P=.015, respectively). There were no significant differences in the rates of MI, stroke and the need for coronary revascularisation procedures, which occurred in 1.1%, 0.43% and 2.24% of the patients with EBPIE, respectively, and occurred in 0.09%, 0.05% and 0.13% of the women without EBPIE (P=.66; P=.57; P=.19, respectively). After a multivariate adjustment, EBPIE was not a predictor of mortality or cardiovascular events.

CONCLUSIONS

EBPIE is not associated with mortality or severe cardiovascular events in women with known or suspected coronary artery disease.

Excessive blood pressure increase with exercise and risk of all-cause mortality and cardiac events

BACKGROUND

The association of an excessive blood pressure increase with exercise (EBPIE) on cardiovascular outcomes remains controversial. We sought to assess its impact on the risk of all-cause mortality and major cardiac events in patients with known or suspected coronary artery disease (CAD) referred for stress testing.

MATERIALS AND METHODS

Exercise echocardiography was performed in 10 047 patients with known or suspected CAD. An EBPIE was defined as an increase in systolic blood pressure with exercise ≥ 80 mmHg. The endpoints were all-cause mortality and major cardiac events (MACE), including cardiac death or nonfatal myocardial infarction (MI).

RESULTS

Overall, 573 patients exhibited an EBPIE during the tests. Over a mean follow-up of 4·8 years, there were 1950 deaths (including 725 cardiac deaths), 1477 MI and 1900 MACE. The cumulative 10-year rates of all-cause mortality, cardiac death, nonfatal MI and MACE were 32·9%, 13·1%, 26·9% and 33% in patients who did not develop an EBPIE vs. 18·9%, 4·7%, 17·5% and 20·7% in those experiencing an EBPIE, respectively (P < 0·001 for all comparisons). In Cox regression analyses, an EBPIE remained predictive of all-cause mortality (hazard ratio [HR] 0·73, 95% confidence interval [CI] 0·59-0·91, P = 0·004), cardiac death (HR 0·67, 95% CI 0·46-0·98, P = 0·04), MI (HR 0·67, 95% CI 0·52-0·86, P = 0·002) and MACE (HR 0·69, 95% CI 0·56-0·86, P = 0·001).

CONCLUSIONS

An EBPIE was associated with a significantly lower risk of mortality and MACE in patients with known or suspected CAD referred for stress testing.

Exaggerated exercise blood pressure response and risk of stroke in patients referred for stress testing

BACKGROUND/OBJECTIVES

There is some evidence to suggest that exercise systolic blood pressure (SBP) may be associated with future risk of stroke in subjects without a history of coronary artery disease (CAD). However, the value of an exaggerated exercise SBP response (EESBPR) for predicting stroke in patients referred for stress testing for clinical reasons has not been investigated.

METHODS

We evaluated a community-based sample of 10,047 patients with known or suspected CAD who underwent treadmill exercise echocardiography. An EESBPR was defined as a peak exercise SBP of >220mmHg. The ratio of the increase in SBP during exercise to exercise workload (ΔSBPeEW) was also estimated. The endpoints were stroke of any type, ischemic stroke and hemorrhagic stroke. Median follow-up was 3.5years.

RESULTS

Annualized rates of stroke of any type, ischemic stroke and hemorrhagic stroke were 0.6% (95% CI 0.53-0.67), 0.49% (95% CI 0.42-0.56) and 0.12% (95% CI 0.09-0.15) in patients without EESBPR vs. 0.69% (95% CI 0.37-1), 0.49% (95% CI 0.23-0.76) and 0.19% (95% CI 0.02-0.35) in those with EESBPR (p=0.68, 0.90 and 0.39, respectively). Similarly, there was no significant univariate association between ΔSBPeEW and the occurrence of any endpoint. In multivariate analysis, hypertension, male sex, age, diabetes mellitus and resting SBP remained predictors of stroke of any type. EESBPR and ΔSBPeEW were not predictors of any of the endpoints evaluated.

CONCLUSION

We did not observe any significant association between exercise SBP and the future occurrence of stroke in patients with known or suspected CAD referred for exercise echocardiography.

Clinical implications of referral bias in the diagnostic performance of exercise testing for coronary artery disease

BACKGROUND

Exercise testing with echocardiography or myocardial perfusion imaging is widely used to risk-stratify patients with suspected coronary artery disease. However, reports of diagnostic performance rarely adjust for referral bias, and this practice may adversely influence patient care. Therefore, we evaluated the potential impact of referral bias on diagnostic effectiveness and clinical decision-making.

METHODS AND RESULTS

Searching PubMed and EMBASE (1990-2012), 2 investigators independently evaluated eligibility and abstracted data on study characteristics and referral patterns. Diagnostic performance reported in 4 previously published meta-analyses of exercise echocardiography and myocardial perfusion imaging was adjusted using pooled referral rates and Bayesian methods. Twenty-one studies reported referral patterns in 49 006 patients (mean age 60.7 years, 39.6% women, and 0.8% prior history of myocardial infarction). Catheterization referral rates after normal and abnormal exercise tests were 4.0% (95% CI, 2.9% to 5.0%) and 42.5% (36.2% to 48.9%), respectively, with odds ratio for referral after an abnormal test of 14.6 (10.7 to 19.9). After adjustment for referral, exercise echocardiography sensitivity fell from 84% (80% to 89%) to 34% (27% to 41%), and specificity rose from 77% (69% to 86%) to 99% (99% to 100%). Similarly, exercise myocardial perfusion imaging sensitivity fell from 85% (81% to 88%) to 38% (31% to 44%), and specificity rose from 69% (61% to 78%) to 99% (99% to 100%). Summary receiver operating curve analysis demonstrated only modest changes in overall discriminatory power but adjusting for referral increased positive-predictive value and reduced negative-predictive value.

CONCLUSIONS

Exercise echocardiography and myocardial perfusion imaging are considerably less sensitive and more specific for coronary artery disease after adjustment for referral. Given these findings, future work should assess the comparative ability of these and other tests to rule-in versus rule-out coronary artery disease.

Stress induced hypertensive response: should it be evaluated more carefully?

Various diagnostic methods have been used to evaluate hypertensive patients under physical and pharmacological stress. Several studies have shown that exercise hypertension has an independent, adverse impact on outcome; however, other prognostic studies have shown that exercise hypertension is a favorable prognostic indicator and associated with good outcome. Exercise hypertension may be encountered as a warning signal of hypertension at rest and future hypertensive left ventricular hypertrophy. The results of diagnostic stress tests support that hypertensive response to exercise is frequently associated with high rate-pressure product in hypertensives. In addition to the observations on high rate-pressure product and enhanced ventricular contractility in patients with hypertension, evaluation of myocardial contractility by Doppler tissue imaging has shown hyperdynamic myocardial function under pharmacological stress. These recent quantitative data in hypertensives suggest that hyperdynamic myocardial function and high rate-pressure product response to stress may be related to exaggerated hypertension, which may have more importance than that it has been already given in clinical practice.

Prognostic value of an exaggerated exercise blood pressure response in patients with diabetes mellitus and known or suspected coronary artery disease

The prognostic value of an exaggerated exercise systolic blood pressure response (EESBPR) remains controversial. Our aim was to assess whether an EESBPR is associated with the long-term outcome in patients with diabetes mellitus and known or suspected coronary artery disease (CAD). From an initial population of 22,262 patients with known or suspected CAD who underwent treadmill exercise electrocardiography or exercise echocardiography at our institution, 2,591 patients with a history of diabetes mellitus were selected for the present study. EESBPR was defined as systolic blood pressure >220 mm Hg during exercise. The end points were all-cause mortality and hard events (ie, death or myocardial infarction). A total of 236 patients (9.1%) developed an EESBPR during the tests. During a mean follow-up of 6.5 +/- 3.9 years, 484 patients died and 646 experienced hard events. The 10-year mortality rate was 16.6% in patients with an EESBPR compared to 30.9% in those without an EESBPR (p <0.001). The 10-year hard event rate was also lower in patients with an EESBPR (23.2% vs 38.9% in patients without an EESBPR; p <0.001). On multivariate analysis, an EESBPR remained independently associated with a lower risk of all-cause mortality (hazard ratio 0.53, 95% confidence interval 0.36 to 0.78, p = 0.001) and hard events (hazard ratio 0.57, 95% confidence interval 0.41 to 0.79; p <0.001). These results remained consistent in the subgroup of patients without a known history of CAD. In conclusion, an EESBPR was associated with improved survival and a lower rate of death or myocardial infarction in patients with diabetes mellitus and known or suspected CAD.