Prognostic value of a nine-minute treadmill test in patients undergoing myocardial perfusion scintigraphy

Comparative effectiveness of exercise electrocardiography versus exercise echocardiography in women presenting with suspected coronary artery disease: a randomized study

Aims

There is a paucity of randomized diagnostic studies in women with suspected coronary artery disease (CAD). This study sought to assess the relative value of exercise stress echocardiography (ESE) compared with exercise electrocardiography (Ex-ECG) in women with CAD.

Methods and results

Accordingly, 416 women with no prior CAD and intermediate probability of CAD (mean pre-test probability 41%), were randomized to undergo either Ex-ECG or ESE. The primary endpoints were the positive predictive value (PPV) for the detection of significant CAD and downstream resource utilization. The PPV of ESE and Ex-ECG were 33% and 30% (P = 0.87), respectively for the detection of CAD. There were similar clinic visits (36 vs. 29, P = 0.44) and emergency visits with chest pain (28 vs. 25, P = 0.55) in the Ex-ECG and ESE arms, respectively. At 2.9 years, cardiac events were 6 Ex-ECG vs. 3 ESE, P = 0.31. Although initial diagnosis costs were higher for ESE, more women underwent further CAD testing in the Ex-ECG arm compared to the ESE arm (37 vs. 17, P = 0.003). Overall, there was higher downstream resource utilization (hospital attendances and investigations) in the Ex-ECG arm (P = 0.002). Using National Health Service tariffs 2020/21 (British pounds) the cumulative diagnostic costs were 7.4% lower for Ex-ECG compared with ESE, but this finding is sensitive to the cost differential between ESE and Ex-ECG.

Conclusion

In intermediate-risk women who are able to exercise, Ex-ECG had similar efficacy to an ESE strategy, with higher resource utilization whilst providing cost savings.

Prognostic Interplay Between Coronary Artery Calcium Scoring and Cardiorespiratory FItness: The CAC-FIT Study

OBJECTIVE

To assess the incremental prognostic role of coronary artery calcium score (CACS) and exercise capacity (EC), two independent prognostic tests in the assessment of patients with coronary artery disease.

METHODS

The cohort consisted of patients who had clinically indicated exercise stress testing and CACS assessment from January 1, 2015, to September 30, 2021, with a median of 27 days between each other. Exercise capacity was defined by peak metabolic equivalents of task (METs) achieved during exercise stress test. The CACS was determined by the Agatston method. Patients were observed from the latest test date to incident major adverse cardiac events (inclusive of all-cause death, nonfatal myocardial infarction, late revascularization, and admission for heart failure).

RESULTS

There were a` total of 1932 patients in the study population (mean age, 56±12 years; 42% female, 48% hypertension, 21% diabetes, 48% dyslipidemia). Peak METs below 6 was achieved in 8% of patients, and the median (interquartile range) CACS was 9 (0-203). In multivariable Cox regression models, both CACS (1 unit increase in log CACS: hazard ratio, 1.19; 95% CI, 1.06 to 1.34; P=.003;) and EC (1 unit increase in peak METs: hazard ratio, 0.89; 95% CI, 0.81 to 0.97; P=.01) were independently associated with outcomes. Using CACS+EC added incremental prognostic value over clinical and fitness models (C index increase from 0.68 to 0.75; P=.015). Incident event rates increased across categories of CACS and EC.

CONCLUSION

Our analysis found that CACS and EC have complementary risk-stratifying roles in coronary artery disease.

Combined effects of exercise capacity and coronary atherosclerotic burden on all-cause mortality in asymptomatic Koreans

BACKGROUND AND AIMS

Both exercise capacity and coronary artery calcium score (CACS) are important prognostic factors in cardiovascular outcome. Yet, whether there is a significant interaction between these two factors in influencing clinical outcome is still uncertain. This study investigated the combined effects of exercise capacity and CACS on all-cause mortality in an asymptomatic population.

METHODS

From multicenter registry of health screening, a retrospective cohort of 25,972 asymptomatic subjects, who underwent both CACS and treadmill exercise test, was included in the final dataset for analysis. Outcome was defined as all-cause mortality, which was obtained from national mortality registry.

RESULTS

The mean age of study subjects was 53.7 ± 7.7 years and 81.5% of them were males. Median follow-up duration was 5.5 (IQR 3.6-7.5) years and 226 (0.9%) cases of all-cause mortality occurred. In multivariate Cox's proportional hazard model with interaction term, exercise capacity ≥10 METs (HR 0.684, 95% CI 0.483-0.971) and CACS ≥400 (HR 3.328, 95% CI 1.850-5.988) were significant predictors of all-cause mortality. In patients with higher exercise capacity, the effect of high CACS on all-cause mortality was significantly smaller than in those with lower exercise capacity. The HR for all-cause mortality of CACS ≥400, in those with lower exercise capacity, is estimated to be about three times of that in those with higher exercise capacity (HR 3.328 in <10 METs vs. 1.108 in ≥10 METs, p for interaction = 0.024) after adjustment for age, gender, fasting glucose, creatinine, alanine transaminase and albumin.

CONCLUSIONS

The effect of high CACS on all-cause mortality is lessened by good exercise capacity in the asymptomatic population. Good physical fitness may reduce the adverse effect of high coronary atherosclerotic burden.

Characteristics and outcomes of patients who achieve high workload (≥10 metabolic equivalents) during treadmill exercise echocardiography

OBJECTIVE

To determine the frequency and prognostic significance of abnormal exercise echocardiographic results for patients achieving a workload of 10 or more metabolic equivalents during treadmill exercise echocardiography.

PATIENTS AND METHODS

Patients who underwent treadmill exercise echocardiography from November 1, 2003, through December 31, 2008, and exercised for 9 or more minutes using the Bruce protocol (N=7236) were included. Clinical and exercise echocardiographic characteristics and outcomes were evaluated. Variables associated with abnormal exercise echocardiographic results and mortality were identified.

RESULTS

Exercise echocardiographic results were positive for ischemia in 862 patients (12%). Extensive ischemia developed in 265 patients (4%). For patients with normal exercise echocardiographic results, all-cause and cardiovascular mortality rates were 0.30% and 0.05% per person-year of follow-up, respectively. For patients who had extensive ischemia, all-cause and cardiovascular mortality rates were 0.84% and 0.25% per person-year of follow-up, respectively. Patients at highest risk were those who had extensive and severe regional wall motion abnormalities at rest (n=58), and their all-cause and cardiovascular mortality rates were 2.65% and 0.76% per person-year of follow-up. Exercise echocardiographic variables did not identify sizable patient subgroups at risk for death and did not provide incremental prognostic information (C statistic was 0.74 compared with 0.73 for the clinical plus exercise electrocardiography model).

CONCLUSION

Patients achieving a workload of 10 or more metabolic equivalents during treadmill exercise testing do not often have extensive ischemic abnormalities on exercise echocardiography. Although exercise echocardiographic results provide some prognostic information, it is not of incremental value for these patients, whose short-term and medium-term prognosis is excellent.

Potential effectiveness of traditional Chinese medicine for cardiac syndrome X (CSX): a systematic review and meta-analysis

BACKGROUND

Treatment of cardiac syndrome X with unknown pathological mechanism remains a big challenge for clinicians. Complementary and alternative medicine may bring a new choice for its management. The aim of this study is to evaluate the clinical effects of traditional Chinese medicine on cardiac syndrome X patients.

METHODS

We systematically searched databases such as Cochrane CENTRAL, PubMed, EMBASE, CBM, Chinese National Knowledge Infrastructure (CNKI), WanFang and VIP, and handsearched relevant journals to identify randomized controlled trials. Following the steps of systematic review recommended by the Cochrane group, we assessed the quality of included studies, extracted valid data and undertook meta-analysis.

RESULTS

Twenty one moderate-to low-quality randomized controlled trials involving 1143 patients were included. The results showed that traditional Chinese medicine could improve angina [OR=1.34, 95% CI: 1.2 to 1.50], electrocardiogram (ECG), endothelin-1 (ET-1) levels, prolong exercise duration in treadmill tests, and reduce angina frequency per week compared with routine treatment. No other side effect was reported except two cases of stomach pain.

CONCLUSION

Compared with conventional treatment, traditional Chinese medicine shows the potential of optimizing symptomatic outcomes and improving ECG and exercise duration. The efficacy of TCM may find explanation in its pharmacological activity of adjusting the endothelial function. TCM, as a kind of alternative and complementary medicine, may provide another choice for CSX patients.

Comparative Effectiveness of Exercise Electrocardiography With or Without Myocardial Perfusion Single Photon Emission Computed Tomography in Women With Suspected Coronary Artery Disease

Background—

There is a paucity of randomized trials regarding diagnostic testing in women with suspected coronary artery disease (CAD). It remains unclear whether the addition of myocardial perfusion imaging (MPI) to the standard ECG exercise treadmill test (ETT) provides incremental information to improve clinical decision making in women with suspected CAD.

Methods and Results—

We randomized symptomatic women with suspected CAD, an interpretable ECG, and ≥5 metabolic equivalents on the Duke Activity Status Index to 1 of 2 diagnostic strategies: ETT or exercise MPI. The primary end point was 2-year incidence of major adverse cardiac events, defined as CAD death or hospitalization for an acute coronary syndrome or heart failure. A total of 824 women were randomized to ETT or exercise MPI. For women randomized to ETT, ECG results were normal in 64%, indeterminate in 16%, and abnormal in 20%. By comparison, the exercise MPI results were normal in 91%, mildly abnormal in 3%, and moderate to severely abnormal in 6%. At 2 years, there was no difference in major adverse cardiac events (98.0% for ETT and 97.7% for MPI; P =0.59). Compared with ETT, index testing costs were higher for exercise MPI ( P <0.001), whereas downstream procedural costs were slightly lower ( P =0.0008). Overall, the cumulative diagnostic cost savings was 48% for ETT compared with exercise MPI ( P <0.001).

Conclusions—

In low-risk, exercising women, a diagnostic strategy that uses ETT versus exercise MPI yields similar 2-year posttest outcomes while providing significant diagnostic cost savings. The ETT with selective follow-up testing should be considered as the initial diagnostic strategy in symptomatic women with suspected CAD.

Clinical Trial Registration—

http://www.clinicaltrials.gov . Unique identifier: NCT00282711.