Cost-effectiveness Analysis of Anatomic vs Functional Index Testing in Patients With Low-Risk Stable Chest Pain.

Importance: Both noninvasive anatomic and functional testing strategies are now routinely used as initial workup in patients with low-risk stable chest pain (SCP). Objective: To determine whether anatomic approaches (ie, coronary computed tomography angiography [CTA] and coronary CTA supplemented with noninvasive fractional flow reserve [FFRCT], performed in patients with 30% to 69% stenosis) are cost-effective compared with functional testing for the assessment of low-risk SCP. Design, Setting, and Participants: This cost-effectiveness analysis used an individual-based Markov microsimulation model for low-risk SCP. The model was developed using patient data from the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial. The model was validated by comparing model outcomes with outcomes observed in the PROMISE trial for anatomic (coronary CTA) and functional (stress testing) strategies, including diagnostic test results, referral to invasive coronary angiography (ICA), coronary revascularization, incident major adverse cardiovascular event (MACE), and costs during 60 days and 2 years. The validated model was used to determine whether anatomic approaches are cost-effective over a lifetime compared with functional testing. Exposure: Choice of index test for evaluation of low-risk SCP. Main Outcomes and Measures: Downstream ICA and coronary revascularization, MACE (death, nonfatal myocardial infarction), cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) of competing strategies. Results: The model cohort included 10 003 individual patients (median [interquartile range] age, 60.0 [54.4-65.9] years; 5270 [52.7%] women; 7693 [77.4%] White individuals), who entered the model 100 times. The Markov model accurately estimated the test assignment, results of anatomic and functional index testing, referral to ICA, revascularization, MACE, and costs at 60 days and 2 years compared with observed data in PROMISE (eg, coronary CTA: ICA, 12.2% [95% CI, 10.9%-13.5%] vs 12.3% [95% CI, 12.2%-12.4%]; revascularization, 6.2% [95% CI, 5.5%-6.9%] vs 6.4% [95% CI, 6.3%-6.5%]; functional strategy: ICA, 8.1% [95% CI, 7.4%-8.9%] vs 8.2% [95% CI, 8.1%-8.3%]; revascularization, 3.2% [95% CI, 2.7%-3.7%] vs 3.3% [95% CI, 3.2%-3.4%]; 2-year MACE rates: coronary CTA, 2.1% [95% CI, 1.7%-2.5%] vs 2.3% [95% CI, 2.2%-2.4%]; functional strategy, 2.2% [95% CI, 1.8%-2.6%] vs 2.4% [95% CI, 2.3%-2.4%]). Anatomic approaches led to higher ICA and revascularization rates at 60 days, 2 years, and 5 years compared with functional testing but were more effective in patient selection for ICA (eg, 60-day revascularization-to-ICA ratio, CTA: 53.7% [95% CI, 53.3%-54.0%]; CTA with FFRCT: 59.5% [95% CI, 59.2%-59.8%]; functional testing: 40.7% [95% CI, 40.4%-50.0%]). Over a lifetime, anatomic approaches gained an additional 6 months in perfect health compared with functional testing (CTA, 25.16 [95% CI, 25.14-25.19] QALYs; CTA with FFRCT, 25.14 [95% CI, 25.12-25.17] QALYs; functional testing, 24.68 [95% CI, 24.66-24.70] QALYs). Anatomic strategies were less costly and more effective; thus, CTA with FFRCT dominated and CTA alone was cost-effective (ICERs ranged from $1912/QALY for women and $3,559/QALY for men) compared with functional testing. In probabilistic sensitivity analyses, anatomic approaches were cost-effective in more than 65% of scenarios, assuming a willingness-to-pay threshold of $100 000/QALY. Conclusions and Relevance: The results of this study suggest that anatomic strategies may present a more favorable initial diagnostic option in the evaluation of low-risk SCP compared with functional testing.

Cost-effectiveness of myocardial perfusion SPECT and stress test according to coronary revascularization therapy, cardiac events and total mortality: Register of 8,496 patients. / Coste-efectividad de la SPECT de perfusión miocárdica y de la prueba de esfuerzo en relación con la revascularización coronaria, eventos cardíacos y mortalidad total. Registro de 8.496 pacientes.

OBJECTIVE: The aim was to analyze the cost-effectiveness ratio (CER) of stress electrocardiogram (ES) and stress myocardial perfusion imaging (SPECT-MPI) according to coronary revascularization (CR) therapy, cardiac events (CE) and total mortality (TM). MATERIAL AND METHODS: A total of 8,496 consecutive patients who underwent SPECT-MPI were followed-up (mean 5.3±3.5years). Cost-effectiveness for coronary bypass (CABG) or percutaneous CR (PCR) (45.6%/54.4%) according to combined electrocardiographic ischemia and scintigraphic ischemia were evaluated. Effectiveness was evaluated as TM, CE, life-year saved observed (LYSO) and CE-LYSO; costs analyses were conducted from the perspective of the health care payer. A sensitivity analysis was performed considering current CABG/PCR ratios (12%/88%). RESULTS: When electrocardiogram and SPECT approaches are combined, the cost-effectiveness values for CABG ranged between 112,589€ (electrocardiographic and scintigraphic ischemia) and 2,814,715€ (without ischemia)/event avoided, 38,664 and 2,221,559€/LYSO; for PCR ranged between 18,824€ (electrocardiographic and scintigraphic ischemia) and 46,377€ (without ischemia)/event avoided, 6,464 and 36,604€/LYSO. To CE: the cost-effectiveness values of the CABG and CPR in presence of electrocardiographic and scintigraphic ischemia were 269,904€/CE-avoided and 24,428€/CE-avoided, respectively; and the €/LYSO of the CABG and PCR were 152,488 and 13,801, respectively. The RCE was maintained for the current proportion of revascularized patients (12%/88%). CONCLUSIONS: Combined ES and SPECT-MPI results, allows differentiation between patient groups, where the PCR and CABG are more cost-effective in different economic frameworks. The major CER in relation to CR, CE and TM occurs in patients with electrocardiographic and scintigraphic ischemia. PCR is more cost-effective than CABG.

Clinical and Economic Implications of Inconclusive Noninvasive Test Results in Stable Patients With Suspected Coronary Artery Disease: Insights From the PROMISE Trial.

BACKGROUND: Inconclusive noninvasive tests complicate the care of patients with suspected coronary artery disease, but their prevalence and impact on management, outcomes, and costs are not well described. METHODS: PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) patients were randomized to stress testing (n=4533) or computed tomographic angiography (CTA; n=4677). We assessed relationships between inconclusive results, subsequent testing, a composite outcome (death, myocardial infarction, or hospitalization for unstable angina), and healthcare expenditures. RESULTS: Overall, 8.0% of tests were inconclusive (9.7% stress, 6.4% CTA). Compared with negative tests, inconclusive tests were more often referred to a second noninvasive test (stress: 14.6% versus 8.5%, odds ratio [OR], 1.91; CTA: 36.5% versus 8.4%, OR, 5.95; P<0.001) and catheterization (stress: 5.5% versus 2.4%, OR, 2.36; CTA: 23.4% versus 4.1%, OR, 6.49; P<0.001), and composite outcomes were higher for both inconclusive tests (stress: 3.7% versus 2.0%, hazard ratio, 1.81, P=0.034; CTA: 5.0% versus 2.2%, hazard ratio, 1.85; P=0.044) and positive tests (stress: 8.3% versus 2.0%, hazard ratio, 3.50; CTA: 9.2% versus 2.2%, hazard ratio, 3.66; P<0.001). Twenty-four-month costs were higher for inconclusive tests than negative tests by $2905 (stress) and $4030 (CTA). CONCLUSIONS: Among patients with stable chest pain undergoing a noninvasive test, inconclusive results occurred in 6% of CTA and 10% of stress tests. Compared with those with conclusive negative tests, individuals with inconclusive results more often underwent subsequent testing, had increased medical costs, and experienced worse outcomes. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01174550.

The Italian preparticipation evaluation programme: diagnostic yield, rate of disqualification and cost analysis.

INTRODUCTION: Italian law mandates that every competitive athlete must undergo annual preparticipation evaluation (PPE) to identify cardiovascular (CV) diseases that pose a risk of sudden death (SD) during sport and other conditions that may threaten the athlete's health. We investigated the diagnostic yield, rate of disqualification and costs of our PPE. METHODS: We included 5910 consecutive apparently healthy athletes (61% males, mean age 15±4 years) who underwent annual PPE performed by a sports medicine specialist. The PPE included history, physical examination, weight, height and blood pressure measurement, test of visual acuity, spirometry, urine chemistry, resting 12-lead ECG and exercise testing with ECG monitoring. In cases of abnormal findings, we carried out second-line investigations. RESULTS: During a 12-month study period, 5.326 (90.2%) athletes were cleared for competition after a normal first-line evaluation and 584 (9.8%) underwent one or more further examinations. Of those, 88 (1.5%) were diagnosed to have a CV disease (including 18 (0.3%) at-risk of SD) and 31 (0.5%) had a non-CV diagnosis. A total of 32 (0.5%) athletes were temporarily (n=15) or permanently (n=17) disqualified from competitive sports. The average cost per athlete was €79, which consisted of €64 (80%) for first-line evaluations and €15 (20%) for additional investigations. CONCLUSION: PPE according to the Italian model identified a range of diseases in 2.0% of apparently healthy athletes at an average cost of €79.

The Stress Test.

I felt good about myself, driving to the free medical clinic that evening. A full professor at a medical school, leaving my warm home on a cold night after a day at the hospital, seeing patients in clinic in the morning and teaching second-year students medical ethics in the afternoon (autonomy was the theme; we'd covered beneficence and maleficence earlier in the week). Once a month, patients with cardiac problems come to the clinic, and this was the night. Two students presented the patient, a middle-aged woman with chest pain. Their presentation was disjointed, in part because of their inexperience, in part because she spoke no English and her story was obtained with the help of a translator. Her eyes rarely met mine; she kept glancing at the translator. I auscultated her heart and lungs, letting the students listen through my stethoscope. What to do now? Had she been a patient that morning back in my clinic, I would have thought to myself, "I can't get a good history; why not do a stress test?" I thought, for what seemed like an eternity: If I send her for a stress test, that will deplete the funds needed for other patients. How important is this test? Is it really necessary? If I send her for a stress test, will someone with a suspicious mass on their chest x-ray not be able to get a CT scan because no money is left?

Design of CTP-PRO study (impact of stress Cardiac computed Tomography myocardial Perfusion on downstream resources and PROgnosis in patients with suspected or known coronary artery disease: A multicenter international study).

BACKGROUND: CT myocardial perfusion imaging (CTP) represents one of the newly developed CT-based techniques but its cost-effectiveness in the clinical pathway is undefined. The aim of the study is to evaluate the usefulness of combined evaluation of coronary anatomy and myocardial perfusion in intermediate to high-risk patients for suspected CAD or with known disease in terms of clinical decision-making, resource utilization and outcomes in a broad variety of geographic areas and patient subgroups. METHODS: CTP-PRO study is a cooperative, international, multicentre, prospective, open-label, randomized controlled study evaluating the cost-effectiveness of a CCTA+CTP strategy (Group A) versus usual care (Group B) in intermediate-high risk patients with suspected or known CAD who undergo clinically indicated diagnostic evaluation. A total sample size of 2000 subjects will be enrolled and followed up for 24 months. The primary endpoint is the reclassification rate of CCTA in group A due to the addition of CTP. The secondary endpoint will be the comparison between groups in terms of non-invasive and invasive downstream testing, prevalence of obstructive CAD at ICA, revascularization, cumulative ED and overall cost during the follow-up at 1- and 2-years. The tertiary endpoint will be the comparison between each group in terms of MACE and cost-effectiveness at 1- and 2-years. CONCLUSIONS: The study will provide information to patients, health care providers and other stakeholders about which strategy could be more effective in the diagnosis of suspected CAD in intermediate to high-risk patients or in the symptomatic patients with known CAD and previous history of revascularization.

Anticipated Rates and Costs of Guideline-Concordant Preoperative Stress Testing.

BACKGROUND: Current guidelines recommend that patients have preoperative assessment of cardiac risk and functional status, and that patients at "elevated" cardiac risk with poor or unknown functional status be referred for preoperative stress testing. Little is known about current rates of testing or resultant medical costs. We set out to estimate the expected rates of preoperative stress testing and resultant costs if physicians in the United States were to follow current guidelines and to investigate differences that would arise from 2 risk prediction methods included in current guidelines. METHODS: We applied 2 risk prediction tools (Revised Cardiac Risk Index and Myocardial Infarction or Cardiac Arrest) included in current American College of Cardiology/American Heart Association guidelines to a multicenter prospective registry of patients undergoing surgery in the United States in 2009. We then calculated expected rates of preoperative cardiac stress testing if physicians were to follow American College of Cardiology/American Heart Association guidelines, expected nationwide direct medical expenditures that would result (in 2017 US dollars), and agreement beyond chance between the 2 risk prediction tools. RESULTS: Current guidelines recommend considerable spending on preoperative stress testing. Guideline-recommended spending would differ substantially depending on the risk prediction tool used and the reliability of the functional status assessment. Rates of testing and resultant spending are likely much greater among patients at "elevated" risk, compared with patients at "low" risk. Two guideline-recommended risk assessment tools, Revised Cardiac Risk Index and Myocardial Infarction or Cardiac Arrest, have poor agreement beyond chance across the currently recommended risk threshold. CONCLUSIONS: Preoperative stress testing is likely a considerable source of medical spending, despite unproven benefit. Which perioperative risk assessment tool clinicians should use, what risk thresholds are appropriate for patient selection, and the reliability of the functional status assessment all warrant further attention.

Cardiorespiratory Fitness (Peak Oxygen Uptake): Safe and Effective Measure for Cardiovascular Screening Before Kidney Transplant.

BACKGROUND: Significant heterogeneity exists in practice patterns and algorithms used for cardiac screening before kidney transplant. Cardiorespiratory fitness, as measured by peak oxygen uptake (VO2peak), is an established validated predictor of future cardiovascular morbidity and mortality in both healthy and diseased populations. The literature supports its use among asymptomatic patients in abrogating the need for further cardiac testing. METHODS AND RESULTS: We outlined a pre-renal transplant screening algorithm to incorporate VO2peak testing among a population of asymptomatic high-risk patients (with diabetes mellitus and/or >50 years of age). Only those with VO2peak <17 mL/kg per minute (equivalent to <5 metabolic equivalents) underwent further noninvasive cardiac screening tests. We conducted a retrospective study of the a priori dichotomization of the VO2peak <17 versus ≥17 mL/kg per minute to determine negative and positive predictive value of future cardiac events and all-cause mortality. We report a high (>90%) negative predictive value, indicating that VO2peak ≥17 mL/kg per minute is effective to rule out future cardiac events and all-cause mortality. However, lower VO2peak had low positive predictive value and should not be used as a reliable metric to predict future cardiac events and/or mortality. In addition, a simple mathematical calculation documented a cost savings of ≈$272 600 in the cardiac screening among our study cohort of 637 patients undergoing evaluation for kidney and/or pancreas transplant. CONCLUSIONS: We conclude that incorporating an objective measure of cardiorespiratory fitness with VO2peak is safe and allows for a cost savings in the cardiovascular screening protocol among higher-risk phenotype (with diabetes mellitus and >50 years of age) being evaluated for kidney transplant.

Cost-effectiveness of a management strategy based on exercise echocardiography versus exercise electrocardiography in patients presenting with suspected angina during long term follow up: A randomized study.

INTRODUCTION: Exercise ECG (Ex-ECG) is advocated by guidelines for patients with low - intermediate probability of coronary artery disease (CAD). However, there are no randomized studies comparing Ex-ECG with exercise stress echocardiography (ESE) evaluating long term cost-effectiveness of each management strategy. METHODS: Accordingly, 385 patients with no prior CAD and low-intermediate probability of CAD (mean pre-test probability 34%), were randomized to undergo either Ex-ECG (194 patients) or ESE (191 patients). The primary endpoint was clinical effectiveness defined as the positive predictive value (PPV) for the detection of CAD of each test. Cost-effectiveness was derived using the cumulative costs incurred by each diagnostic strategy during a mean of follow up of 3.0 years. RESULTS: The PPV of ESE and Ex-ECG were 100% and 64% (p = 0.04) respectively for the detection of CAD. There were fewer clinic (31 vs 59, p < 0.01) and emergency visits (14 vs 30, p = 0.01) and lower number of hospital bed days (8 vs 29, p < 0.01) in the ESE arm, with fewer patients undergoing coronary angiography (13.4% vs 6.3%, p = 0.02). The overall cumulative mean costs per patient were £796 for Ex-ECG and £631 for ESE respectively (p = 0.04) equating to a >20% reduction in cost with an ESE strategy with no difference in the combined end-point of death, myocardial infarction, unplanned revascularization and hospitalization for chest pain between ESE and Ex-ECG (3.2% vs 3.7%, p = 0.38). CONCLUSION: In patients with low to intermediate pretest probability of CAD and suspected angina, an ESE management strategy is cost-effective when compared with Ex-ECG during long term follow up.

Comparative efficiency of exercise stress testing with and without stress-only myocardial perfusion imaging in patients with low-risk chest pain.

OBJECTIVES: To compare major adverse cardiac event (MACE), downstream resource utilization, and direct cost of care for low-risk chest pain patients observed in the clinical decision unit (CDU) with exercise treadmill testing (ETT) and with stress-only myocardial perfusion imaging (sMPI). BACKGROUND: CDUs are poised to increase efficiency and resource utilization. However, the optimal testing strategy that would assure favorable outcomes while decreasing cost is not defined. METHODS: 1016 subjects from 2 locations were propensity score-matched (PSM) by age, gender, pre-test likelihood, Duke treadmill score, and test results. Outcomes were length of stay >24 hours, MACE (acute coronary syndrome, revascularization, cardiac death), downstream resource use (admission for chest pain, repeat testing, angiography), and mean direct cost per patient. RESULTS: PSM yielded 680 patients (340 matches). 98% of all tests were normal. 96.6% of patients were discharged from the CDU within 24 hours but twice as many exceeded 24 hours in the sMPI group. There were no cardiac deaths. MACE rate was 1.47% at 72 hours and 1% at 1 year. Downstream resource use was 4.82% at 72 hours, and 7.69% at 1 year. The sMPI group was event-free longer than the ETT group reflecting less repeat testing. The mean direct cost was 30% higher for sMPI ($3168.70) vs. ETT ($2226.96). CONCLUSION: Low-risk chest pain patients in the observation unit had low MACE rate, not different for ETT vs. sMPI. The majority of ETT and sMPI tests were normal. The sMPI reduced additional testing, but resulted in greater expense and longer stay.

Application of exercise ECG stress test in the current high cost modern-era healthcare system.

Exercise electrocardiogram (ECG) tests boasts of being more widely available, less resource intensive, lower cost and absence of radiation. In the presence of a normal baseline ECG, an exercise ECG test is able to generate a reliable and reproducible result almost comparable to Technitium-99m sestamibi perfusion imaging. Exercise ECG changes when combined with other clinical parameters obtained during the test has the potential to allow effective redistribution of scarce resources by excluding low risk patients with significant accuracy. As we look towards a future of rising healthcare costs, increased prevalence of cardiovascular disease and the need for proper allocation of limited resources; exercise ECG test offers low cost, vital and reliable disease interpretation. This article highlights the physiology of the exercise ECG test, patient selection, effective interpretation, describe previously reported scores and their clinical application in today's clinical practice.

Cost-effectiveness of anatomical and functional test strategies for stable chest pain: public health perspective from a middle-income country.

OBJECTIVES: The aim of this research is to evaluate the relative cost-effectiveness of functional and anatomical strategies for diagnosing stable coronary artery disease (CAD), using exercise (Ex)-ECG, stress echocardiogram (ECHO), single-photon emission CT (SPECT), coronary CT angiography (CTA) or stress cardiacmagnetic resonance (C-MRI). SETTING: Decision-analytical model, comparing strategies of sequential tests for evaluating patients with possible stable angina in low, intermediate and high pretest probability of CAD, from the perspective of a developing nation's public healthcare system. PARTICIPANTS: Hypothetical cohort of patients with pretest probability of CAD between 20% and 70%. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome is cost per correct diagnosis of CAD. Proportion of false-positive or false-negative tests and number of unnecessary tests performed were also evaluated. RESULTS: Strategies using Ex-ECG as initial test were the least costly alternatives but generated more frequent false-positive initial tests and false-negative final diagnosis. Strategies based on CTA or ECHO as initial test were the most attractive and resulted in similar cost-effectiveness ratios (I$ 286 and I$ 305 per correct diagnosis, respectively). A strategy based on C-MRI was highly effective for diagnosing stable CAD, but its high cost resulted in unfavourable incremental cost-effectiveness (ICER) in moderate-risk and high-risk scenarios. Non-invasive strategies based on SPECT have been dominated. CONCLUSIONS: An anatomical diagnostic strategy based on CTA is a cost-effective option for CAD diagnosis. Functional strategies performed equally well when based on ECHO. C-MRI yielded acceptable ICER only at low pretest probability, and SPECT was not cost-effective in our analysis.

Cost-effectiveness of diagnostic evaluation strategies for individuals with stable chest pain syndrome and suspected coronary artery disease.

PURPOSE: To determine lifetime cost-effectiveness of diagnostic evaluation strategies for individuals with stable chest pain and suspected coronary artery disease (CAD). METHODS: Exercise treadmill testing (ETT), stress echocardiography (SE), myocardial perfusion scintigraphy (MPS), coronary computed tomographic angiography (CCTA), and invasive coronary angiography (ICA) were assessed alone, or in succession to each other. RESULTS: Initial ETT followed by imaging wherein ETT was equivocal or unable to be performed appeared more cost-effective than any strategy employing initial testing by imaging. CONCLUSION: As pre-test likelihood of CAD varies, different modalities including SE, CCTA, and MPS result in improved costs and enhanced effectiveness.

The medical value and cost-effectiveness of an exercise test for sport preparticipation evaluation in asymptomatic middle-aged white male and female athletes.

BACKGROUND: Cardiovascular events related to high-intensity sport practice are rare but dramatic. Coronary artery disease (CAD) is the leading cause of these events after the age of 35 years. The value of a maximal exercise test (ET) for detection of athletes at risk remains a matter of debate. AIM: The aim of this prospective multicentre study was to clarify the medical value and cost-effectiveness of an ET in middle-aged white asymptomatic athletes who participate in high-intensity sport. METHODS: All athletes had a physical examination, assessment of cardiovascular risk factors, a resting electrocardiogram and an ET. In case of abnormal ET, complementary cardiovascular evaluation was performed, when requested, to detect potential cardiovascular disease. RESULTS: 1361 asymptomatic athletes (mean age 50.4±9.6 years; mean training 5.1±3.2h/week; 10.4% women) with a normal resting electrocardiogram and without cardiovascular disease were consecutively included. An abnormal ET was reported in 144 subjects (94% men); this was positively related to the subject's age and cardiovascular risk level. Cardiac arrhythmias (48%) and CAD symptoms (33.3%) were mainly reported. Cardiovascular disease was confirmed in 24 cases (1.7% from the whole population; 16.7% from those with an abnormal ET) - mainly CAD (n=12) and arterial hypertension (n=8). Seventy athletes presented significant unexplained arrhythmias. The cost was approximately €8450 for every confirmed case of cardiovascular disease. CONCLUSIONS: In this multicentre study in middle-aged athletes, a systematic ET was abnormal in 10.6% of cases. About 2% of subjects had cardiovascular disease, mainly arrhythmias and CAD. From these results, it seems that in a trained population aged >35 years, ET should be targeted at men with at least two cardiovascular risk factors, with acceptable cost-effectiveness.

A low-cost Mr compatible ergometer to assess post-exercise phosphocreatine recovery kinetics.

OBJECTIVE: To develop a low-cost pedal ergometer compatible with ultrahigh (7 T) field MR systems to reliably quantify metabolic parameters in human lower leg muscle using phosphorus magnetic resonance spectroscopy. MATERIALS AND METHODS: We constructed an MR compatible ergometer using commercially available materials and elastic bands that provide resistance to movement. We recruited ten healthy subjects (eight men and two women, mean age ± standard deviation: 32.8 ± 6.0 years, BMI: 24.1 ± 3.9 kg/m2). All subjects were scanned on a 7 T whole-body magnet. Each subject was scanned on two visits and performed a 90 s plantar flexion exercise at 40% maximum voluntary contraction during each scan. During the first visit, each subject performed the exercise twice in order for us to estimate the intra-exam repeatability, and once during the second visit in order to estimate the inter-exam repeatability of the time constant of phosphocreatine recovery kinetics. We assessed the intra and inter-exam reliability in terms of the within-subject coefficient of variation (CV). RESULTS: We acquired reliable measurements of PCr recovery kinetics with an intra- and inter-exam CV of 7.9% and 5.7%, respectively. CONCLUSION: We constructed a low-cost pedal ergometer compatible with ultrahigh (7 T) field MR systems, which allowed us to quantify reliably PCr recovery kinetics in lower leg muscle using 31P-MRS.

Relative clinical and economic impact of exercise echocardiography vs. exercise electrocardiography, as first line investigation in patients without known coronary artery disease and new stable angina: a randomized prospective study.

AIMS: Exercise electrocardiography (ExECG) is widely used in suspected stable angina (SA) as the initial test for the evaluation of coronary artery disease (CAD). We hypothesized that exercise stress echo (ESE) would be efficacious with cost advantage over ExECG when utilized as the initial test. METHODS AND RESULTS: Consecutive patients with suspected SA, without known CAD were randomized into ExECG or ESE. Patients with positive tests were offered coronary angiography (CA) and with inconclusive tests were referred for further investigations. All patients were followed-up for cardiac events (death, myocardial infarction, and unplanned revascularization). Cost to diagnosis of CAD was calculated by adding the cost of all investigations, up to and including CA. In the 194 and 191 patients in the ExECG vs. ESE groups, respectively, pre-test probability of CAD was similar (34 ± 23 vs. 35 ± 25%, P = 0.6). Results of ExECG were: 108 (55.7%) negative, 14 (7.2%) positive, 72 (37.1%) inconclusive and of ESE were 181 (94.8%) negative, 9 (4.7%) positive, 1 (0.5%) inconclusive, respectively. Patients with obstructive CAD following positive ESE vs. Ex ECG were 9/9 vs. 9/14, respectively (P = 0.04). Cost to diagnosis of CAD was £266 for ESE vs. £327 for ExECG (P = 0.005). Over a mean follow-up period of 21 ± 5 months, event rates were similar between the two groups. CONCLUSION: In this first randomized study, ESE was more efficacious and demonstrated superior cost-saving, compared with ExECG when used as the initial investigation for the evaluation of CAD in patients with new-onset suspected SA without known CAD.

Cost analysis of the History, ECG, Age, Risk factors, and initial Troponin (HEART) Pathway randomized control trial.

INTRODUCTION: The HEART Pathway is a diagnostic protocol designed to identify low-risk patients presenting to the emergency department with chest pain that are safe for early discharge. This protocol has been shown to significantly decrease health care resource utilization compared with usual care. However, the impact of the HEART Pathway on the cost of care has yet to be reported. METHODS AND RESULTS: We performed a cost analysis of patients enrolled in the HEART Pathway trial, which randomized participants to either usual care or the HEART Pathway protocol. For low-risk patients, the HEART Pathway recommended early discharge from the emergency department without further testing. We compared index visit cost, cost at 30 days, and cardiac-related health care cost at 30 days between the 2 treatment arms. Costs for each patient included facility and professional costs. Cost at 30 days included total inpatient and outpatient costs, including the index encounter, regardless of etiology. Cardiac-related health care cost at 30 days included the index encounter and costs adjudicated to be cardiac-related within that period. Two hundred seventy of the 282 patients enrolled in the trial had cost data available for analysis. There was a significant reduction in cost for the HEART Pathway group at 30 days (median cost savings of $216 per individual), which was most evident in low-risk (Thrombolysis In Myocardial Infarction score of 0-1) patients (median savings of $253 per patient) and driven primarily by lower cardiac diagnostic costs in the HEART Pathway group. CONCLUSIONS: Using the HEART Pathway as a decision aid for patients with undifferentiated chest pain resulted in significant cost savings.

Cost-effectiveness of exercise stress testing performed as part of executive health examinations.

BACKGROUND: An executive health examination is offered at many hospitals for "busy executives" that comprises of a typical history and examination along with screening tests for major cardiovascular and respiratory illnesses. Exercise stress tests are also frequently included in such packages, though the appropriateness of such stress testing remains uncertain. AIM: To assess the appropriateness and cost-effectiveness of exercise stress tests performed as part of executive health examinations. MATERIALS AND METHODS: Records of all individuals who underwent an executive health examination at our institution between January, 2007 and December, 2012 were retrospectively reviewed. Data were collected pertaining to demographics, cardiovascular risk factors, indication of stress testing and results of exercise stress tests. RESULTS: Of a total of 1650 subjects who underwent exercise stress tests as part of executive health examinations, indication for exercise stress testing was class IIb or III (as per American College of Cardiology's appropriateness criteria) in 96.1 % of subjects. The cumulative cost and time burden of testing for these subjects were Rs. 11,419,200/- PKR (≈$114,192 USD) and 2 weeks and 4 days, respectively. Exercise stress tests were not positive for ischemia in any such cases. CONCLUSION: Based on the results of this study, exercise stress tests should not be routinely offered as part of executive health examinations.

Cardiovascular Testing in Asymptomatic Patients: Carotid Duplex, Cardiac Stress Testing, Screen for Peripheral Arterial Disease.

Approximately one-third of deaths in the United States are from cardiovascular disease. Managing modifiable risk factors is paramount to reducing risk of heart disease and stroke. It is logical to try to identify patients with silent disease that may predispose them to significant morbidity and mortality. Unfortunately, it is unclear if routine screening for the presence of carotid stenosis, coronary artery disease, and peripheral arterial disease is beneficial. Many of these tests are expensive. This review explores the evidence behind screening tests, costs associated with the tests, and the implications of positive screening for each of the 3 listed conditions.