Cost-effectiveness analysis of noninvasive strategies to evaluate patients with chest pain

The role of stress echocardiography in the evaluation of coronary artery disease and myocardial ischemia in women

Considering the unfavorable prognosis of women with ischemic heart disease, an aggressive but safe approach to evaluate women presenting with chest pain is warranted so that coronary artery disease (CAD) can be identified and treated early. Stress echocardiography (SE) has matured into an invaluable technique for the noninvasive detection of obstructive epicardial CAD. Its versatility, accuracy, safety, noninvasiveness, and lack of radiation exposure make SE an attractive technique to apply to the assessment of women with known or suspected heart disease. This article focuses on the current evidence supporting the role of SE in the assessment of CAD and myocardial ischemia in women.

Coronary Artery Calcium Testing in Symptomatic Patients: An Issue of Diagnostic Efficiency

The detection and quantification of coronary artery calcification (CAC) significantly improves cardiovascular risk prediction in asymptomatic patients. Many have advocated for expanded CAC testing in symptomatic patients based on data demonstrating that the absence of quantifiable CAC in patients with possible angina makes obstructive coronary artery disease (CAD) and subsequent adverse events highly unlikely. However, the widespread use of CAC testing in symptomatic patients may be limited by the high background prevalence of CAC and its low specificity for obstructive CAD, necessitating additional testing ('test layering') in a large percentage of eligible patients. Further, adequately powered prospective studies validating the comparative effectiveness of a 'CAC first' approach with regards to cost, safety, accuracy and clinical outcomes are lacking. Due to marked reductions in patient radiation exposure and higher comparative accuracy and prognostic value make coronary computed tomographic angiography the preferred CT-based test for appropriately selected symptomatic patients.

Cost-effectiveness and future implications for cardiovascular imaging

This review highlights the current economic climate for health care and the evidentiary standards that are increasingly applied to appropriate use of cardiovascular imaging. Additionally, the evidence on cost efficiency and effectiveness is explored in this review. Ongoing multicentre registries and clinical trials will further enrich this evidence base with regard to value-based imaging strategies that provide enhanced effectiveness and efficiency resulting in improved patient outcomes.

Prognostic effect of coronary flow reserve in women versus men with chest pain syndrome and normal dipyridamole stress echocardiography

The aim of this study was to investigate the prognostic effect of coronary flow reserve (CFR) on left anterior descending artery (LAD) in women and men with chest pain of unknown origin and normal stress echocardiogram. The study population consisted of 1,660 patients (906 women, 754 men) with chest pain syndrome, no wall motion abnormality on echocardiogram at rest, and dipyridamole (up to 0.84 mg/kg over 6 minutes) stress echocardiogram negative for wall motion criteria. All had undergone stress echocardiography with combined evaluation of CFR on LAD by Doppler. A CFR value ≤2.0 was considered abnormal. Median duration of follow-up was 19 months (interquartile range 10 to 34). Abnormal CFR was assessed in 171 women (19%) and 147 men (19%, p = 0.80). During follow-up, 80 events (20 deaths, 13 ST-elevation myocardial infarctions, and 47 non-ST-elevation myocardial infarctions) occurred. In addition, 128 patients underwent revascularization and were censored. CFR ≤2.0 on LAD was independently associated with prognosis in women (hazard ratio [HR] 16.48, 95% confidence interval [CI] 7.17 to 37.85, p <0.0001) and in men (HR 6.23, 95% CI 3.42 to 11.33, p <0.0001). Antianginal therapy at time of testing (HR 2.11, 95% CI 1.14 to 3.90, p = 0.02) was also a multivariable prognostic predictor in men. Four-year event rate associated with CFR values ≤2.0 and >2.0 were, respectively, 27% and 2% in women (p <0.0001) and 42% and 8% in men (p <0.0001). In conclusion, decreased CFR on LAD is associated with markedly increased risk in women and men with chest pain syndrome and a normal result of dipyridamole stress echocardiography. Conversely, preserved CFR on LAD predicts excellent survival, particularly in women.

Economic analysis including long-term risks and costs of alternative diagnostic strategies to evaluate patients with chest pain

BACKGROUND

Diagnosis costs for cardiovascular disease waste a large amount of healthcare resources. The aim of the study is to evaluate the clinical and economic outcomes of alternative diagnostic strategies in low risk chest pain patients.

METHODS

We evaluated direct and indirect downstream costs of 6 strategies: coronary angiography (CA) after positive troponin I or T (cTn-I or cTnT) (strategy 1); after positive exercise electrocardiography (ex-ECG) (strategy 2); after positive exercise echocardiography (ex-Echo) (strategy 3); after positive pharmacologic stress echocardiography (PhSE) (strategy 4); after positive myocardial exercise stress single-photon emission computed tomography with technetium Tc 99m sestamibi (ex-SPECT-Tc) (strategy 5) and direct CA (strategy 6).

RESULTS

The predictive accuracy in correctly identifying the patients was 83,1% for cTn-I, 87% for cTn-T, 85,1% for ex-ECG, 93,4% for ex-Echo, 98,5% for PhSE, 89,4% for ex-SPECT-Tc and 18,7% for CA. The cost per patient correctly identified results $2.051 for cTn-I, $2.086 for cTn-T, $1.890 for ex-ECG, $803 for ex-Echo, $533 for PhSE, $1.521 for ex-SPECT-Tc ($1.634 including cost of extra risk of cancer) and $29.673 for CA ($29.999 including cost of extra risk of cancer). The average relative cost-effectiveness of cardiac imaging compared with the PhSE equal to 1 (as a cost comparator), the relative cost of ex-Echo is 1.5x, of a ex-SPECT-Tc is 3.1x, of a ex-ECG is 3.5x, of cTnI is x3.8, of cTnT is x3.9 and of a CA is 56.3x.

CONCLUSION

Stress echocardiography based strategies are cost-effective versus alternative imaging strategies and the risk and cost of radiation exposure is void.

Comparison of early dobutamine stress echocardiography and exercise electrocardiographic testing for management of patients presenting to the emergency department with chest pain

This study compared the cost-effectiveness of dobutamine-atropine stress echocardiography (DASE) and electrocardiographic exercise testing (EET) implemented in emergency department accelerated diagnostic protocols for the early stratification of low-risk patients presenting with acute chest pain (ACP). One hundred ninety-nine patients with ACP, nondiagnostic electrocardiographic results, and negative biomarker results were randomized to DASE (n = 110) or EET (n = 89) <6 hours after emergency department presentation. Patients with negative risk assessment results were immediately discharged and followed for 2 months. Ninety patients (82%) in the DASE arm and 78 (88%) in the EET arm were discharged after the diagnosis of nonischemic ACP. The mean lengths of stay in the hospital were 23 +/- 12 and 31 +/- 23 hours in the DASE and EET arms, respectively (p = 0.01). No 2-month follow-up events occurred in DASE patients, and the event rate was significantly higher in EET patients (0% vs 11%, p = 0.004). The DASE strategy showed lower costs compared with the EET strategy at 1-month ($1,026 +/- $250 vs $1,329 +/- $1,288, p = 0.03) and 2-month ($1,029 +/- 253 vs $1,684 +/- $2,149, p = 0.005) follow-up. In conclusion, early DASE in emergency department triage of low-risk patients with ACP is safe and reduces costs of care compared to EET.

Myocardial infarction redefined: impact on case-load and outcome of patients with suspected acute coronary syndrome and nondiagnostic ECG at presentation

Risk stratification of chest pain (CP) is still debated. Objective of this study was to evaluate the performance of a risk stratification model for patients with suspected acute coronary syndrome (ACS) and nondiagnostic ECG at presentation, in whom the occurrence of myocardial infarction was either diagnosed following traditional (t-MI) or the recently redefined (r-MI) criteria. First-line 6-h work-up categorized 3068 patients with suspected ACS and nondiagnostic ECG into low-risk for short-term coronary events, intermediate-risk who entered second-line work-up, and high-risk. Intermediate-risk patients with positive second-line work-up and high-risk patients were considered for urgent coronary angiography. Angina, non-fatal MI, sudden death, and revascularization constituted composite end-point (CE) for in-hospital and 6-month outcome. ACS incidence was 16%; r-MI increased by 62% the diagnosis of MI over t-MI. Among 2024 discharged low-risk patients, 12 (0.6%) had non-fatal CE at 6 months. ACS was diagnosed in 19% of 503 intermediate-risk and 96% of 389 high-risk patients. Among ACS patients, in-hospital CE occurred in 14% of t-MI, 7% of r-MI, and 9% of unstable angina (UA) patients (t-MI vs. r-MI and t-MI vs. UA: p<0.05, for both); 6-month CE occurred in 23%, 16% and 12% of t-MI, r-MI and UA, respectively (t-MI vs. UA: p<005). Sensitivity, specificity and accuracy were high both for diagnostic (97%, 98%, 99%, respectively) and treatment (83%, 98%, 97%, respectively) strategy. Risk stratification, and categorization according to traditional or redefined MI and UA criteria allow safe allocation of resources in CP patients with suspected ACS and nondiagnostic ECG at presentation because outcome is accurately predicted.