Stress myocardial perfusion single-photon emission computed tomography is clinically effective and cost effective in risk stratification of patients with a high likelihood of coronary artery disease (CAD) but no known CAD

OBJECTIVES: We sought to evaluate the prognostic and cost implications of stress myocardial perfusion single-photon emission computed tomography (SPECT), or MPS, in patients with a high pretest likelihood (>0.85) of coronary artery disease (CAD) with no previous CAD. BACKGROUND: Sparse data are available regarding the prognostic performance characteristics of MPS in this patient group. METHOD: We followed up 1,270 consecutive patients with no previous revascularization or myocardial infarction (MI), with a pre-exercise tolerance test (ETT) likelihood of CAD > or =0.85, who underwent exercise or adenosine stress MPS (follow-up 94.4% complete; 2.2 +/- 1.2 years; 60 hard events [5.9%, 2.6%/year]). Risk adjustment of survival data was done using Cox proportional hazards analysis. Costs per reclassification of risk were calculated using assumed costs and threshold analyses. RESULTS: In patients treated medically after MPS, normal MPS had a low risk of cardiac death and hard events (0.6% and 1.3% per year, respectively). With increasing extent and severity of MPS defects, the risk of both cardiac death and hard events increased significantly (p < 0.05). Cox models indicated that the addition of MPS data resulted in incremental prognostic value over pre-MPS data (chi-square increase 48 to 87, p < 0.0001). Compared with strategies of initial referral to ETT in patients able to exercise, initial referral to MPS appeared to be a more cost-effective strategy. Similarly, compared with a strategy of direct referral to catheterization in patients with a high likelihood of CAD, initial referral to MPS is a cost-saving approach. CONCLUSIONS: In patients with a high likelihood of CAD but without known CAD, stress MPS yields incremental value and achieves risk stratification in a cost-effective manner. The current results support a strategy of initial stress imaging in this patient cohort, as a reasonable alternative to direct referral to catheterization or initial ETT.     

Prognostic value of myocardial perfusion imaging in patients with high exercise tolerance

BACKGROUND: Although high exercise tolerance is associated with an excellent prognosis, the significance of abnormal myocardial perfusion imaging (MPI) in patients with high exercise tolerance has not been established. This study retrospectively compares the utility of MPI and exercise ECG (EECG) in these patients. METHODS AND RESULTS: Of 388 consecutive patients who underwent exercise MPI and reached at least Bruce stage IV, 157 (40.5%) had abnormal results and 231 (59.5%) had normal results. Follow-up was performed at 18+/-2.7 months. Adverse events, including revascularization, myocardial infarction, and cardiac death, occurred in 40 patients. Nineteen patients had revascularization related to the MPI results or the patient's condition at the time of MPI and were not included in further analysis. Seventeen patients (12.2%) with abnormal MPI and 4 (1.7%) with normal MPI had adverse cardiac events (P<0.001). Cox proportional-hazards regression analysis showed that MPI was an excellent predictor of cardiac events (global chi2=13.2; P<0.001; relative risk=8; 95% CI=3 to 23) but EECG had no predictive power (global chi2=0.05; P=0.8; relative risk=1; 95% CI=0.4 to 3.0). The addition of Duke's treadmill score risk categories did not improve the predictive power of EECG (global chi2=0.17). The predictive power of the combination of EECG (including Duke score categories) and MPI was no better than that of MPI alone (global chi2=13.5). CONCLUSIONS: Unlike EECG, MPI is an excellent prognostic indicator for adverse cardiac events in patients with known or suspected CAD and high exercise tolerance.     

Evaluation of the patient with diabetes mellitus and suspected coronary artery disease

Coronary artery disease (CAD) is the leading cause of morbidity and mortality in patients with diabetes mellitus. In fact, patients with diabetes have the same risk of myocardial infarction as do nondiabetic subjects with a history of infarction. For this reason, diabetes has been designated by the American College of Cardiology (ACC) and the American Heart Association (AHA) as a CAD equivalent. For women, data indicate a substantially elevated risk of cardiovascular disease (CVD) even before a clinical diagnosis of type 2 diabetes has been made. Identifying patients with diabetes who have CAD and who will benefit from medical and/or invasive intervention to prevent cardiovascular events is a challenge in both symptomatic and asymptomatic patients. The decision to evaluate patients with diabetes who are asymptomatic for CAD presents the greatest challenge; investigation will reveal 10% to 15% of these patients to have CAD. Current diagnostic tools include exercise tolerance testing, stress echocardiography, stress myocardial perfusion imaging (MPI), and cardiac catheterization. Few guidelines are available to aid in the choice of testing modalities for a given patient. Although cardiac catheterization is useful, it is generally reserved for patients in whom invasive intervention is suitable. The American Diabetes Association (ADA) recommends exercise tolerance testing alone in symptomatic patients with > or = 2 CAD risk factors or an abnormal resting electrocardiogram (ECG). However, that recommendation is not based on data; it is the consensus of an expert panel. Stress echocardiography is a useful, noninvasive procedure; however, there is limited experience with this technology in the diabetic population. Recently accumulated data support both diagnostic and prognostic roles for stress MPI, particularly with ECG-gated single-photon emission computed tomographic imaging. In symptomatic patients with diabetes, the presence and extent of abnormal stress MPI findings have been found to be highly accurate independent predictors of subsequent cardiac events: 18% to 26% of asymptomatic patients with diabetes have perfusion defects consistent with CAD. However, CVD risk factors are not predictive of abnormal MPI findings even though duration of diabetes and abnormal ECGs are. The results of future studies may be helpful in guiding the selection of asymptomatic patients to undergo myocardial perfusion and function studies. In conclusion, MPI provides clinicians with an important diagnostic tool, because it offers perfusion as well as functional information for diagnosis and risk stratification in patients with diabetes. These capabilities facilitate decision making regarding the appropriateness of medical therapy or surgical intervention in these individuals.     

Stress echocardiography is superior to exercise ECG in the risk stratification of patients presenting with acute chest pain with negative Troponin.

OBJECTIVE: To compare exercise electrocardiography (ExECG) and stress echocardiography (SE) in the risk stratification of patients presenting to hospital with cardiac-sounding chest pain, non-diagnostic ECGs and negative cardiac Troponin. METHODS: Patients presenting with acute chest pain were prospectively randomised to early ExECG or SE. A post-test likelihood of CAD was determined by the pre-test likelihood and the result of the stress test. Patients with a low post-test likelihood of CAD were discharged; those with a high post-test probability were considered for coronary angiography. All others were managed according to standard hospital protocols. RESULTS: A total of 302 patients underwent either ExECG or SE. SE identified significantly more patients with a low post-test probability of CAD (80% vs 31%, p<0.0001) and significantly fewer patients with an intermediate post-test likelihood of CAD compared to ExECG (3% vs 47%; p<0.0001). Significantly fewer patients undergoing SE were referred for further tests to exclude or refute the diagnosis of CAD (16% vs 52%; p<0.0001). In total, 36 (12%) had flow limiting CAD demonstrated by coronary angiography. Significant CAD was seen in fewer patients with a positive ExECG than with a positive SE (56% vs 84% (p=0.12)). Event rates were low for both modalities in patients with low post-test probability (3.5% for SE vs 5.1% for ExECG; p=ns) though the number of patients identified as low risk was higher if SE was performed. CONCLUSION: Despite negative cardiac Troponin, 12% of patients with acute chest pain had significant CAD. SE is superior to ExECG in discriminating between those patients with a low and intermediate risk of CAD and correctly identified patients with significant CAD, as well as conferring an excellent prognosis in those considered low risk. SE significantly reduces the requirement for further tests to diagnose CAD compared to ExECG.     

Women with high exercise tolerance and the role of myocardial perfusion imaging

BACKGROUND: Myocardial perfusion imaging (MPI) provides incremental diagnostic and prognostic information, even in patients with high exercise tolerance. HYPOTHESIS: Myocardial perfusion imaging provides significant diagnostic value, specifically in women with high exercise tolerance. METHODS: Our study population consisted of all women who underwent exercise MPI in our Department from January 1992 to June 1996 and reached at least Stage IV in the Bruce protocol. Patients were divided into those with known and those with possible coronary artery disease (CAD). All patients were followed for 3 years from the performance of MPI. RESULTS: Of 4,803 women who underwent myocardial perfusion imaging, 3,183 had exercise stressing, and of those, 311 reached at least Stage IV in the Bruce protocol. Of these 311 MPI scans, only 23 (7.4%) were abnormal (reversible, fixed, or mixed) and the remaining 288 (92.6%) were normal. Of the 82 patients with known CAD, 13 (15.8%) had an abnormal MPI, while only 10 (4.4%) of the 229 patients with possible CAD. No myocardial infarction or cardiac death occurred within 3 years; one patient with normal MPI needed revascularization. CONCLUSION: In women with high exercise tolerance, especially in those without already known CAD, the yield of MPI is very low. Women with high exercise tolerance have an excellent prognosis.     

The prognostic value of normal exercise myocardial perfusion imaging and exercise echocardiography: a meta-analysis.

OBJECTIVES: The purpose of this work was to determine the prognostic value of normal exercise myocardial perfusion imaging (MPI) tests and exercise echocardiography tests, and to determine the prognostic value of these imaging modalities in women and men. BACKGROUND: Exercise MPI and exercise echocardiography provide prognostic information that is useful in the risk stratification of patients with suspected coronary artery disease (CAD). METHODS: We searched the PubMed, Cochrane, and DARE databases between January 1990 and May 2005, and reviewed bibliographies of articles obtained. We included prospective cohort studies of subjects who underwent exercise MPI or exercise echocardiography for known or suspected CAD, and provided data on primary outcomes of myocardial infarction (MI) and cardiac death with at least 3 months of follow-up. Secondary outcomes (unstable angina, revascularization procedures) were abstracted if provided. Studies performed exclusively in patients with CAD were excluded. RESULTS: The negative predictive value (NPV) for MI and cardiac death was 98.8% (95% confidence interval [CI] 98.5 to 99.0) over 36 months of follow-up for MPI, and 98.4% (95% CI 97.9 to 98.9) over 33 months for echocardiography. The corresponding annualized event rates were 0.45% per year for MPI and 0.54% per year for echocardiography. In subgroup analyses, annualized event rates were <1% for each MPI isotope, and were similar for women and men. For secondary events, MPI and echocardiography had annualized event rates of 1.25% and 0.95%, respectively. CONCLUSIONS: Both exercise MPI and exercise echocardiography have high NPVs for primary and secondary cardiac events. The prognostic utility of both modalities is similar for both men and women.     

Value of definitive diagnostic testing in the evaluation of patients presenting to the emergency department with chest pain

The optimal diagnostic evaluation of patients presenting to the emergency department (ED) with chest pain but without myocardial infarction or unstable angina is controversial. We performed a prospective, nonrandomized, observational study of 1,195 consecutive patients presenting to the ED with chest pain but who had normal or nondiagnostic electrocardiograms and negative cardiac biomarkers. Patients (mean ± SD age 61 ± 15 years; 55% women) were admitted to the hospital and a standard protocol for evaluation and treatment was suggested. The use of stress myocardial perfusion imaging (MPI) or cardiac catheterization during their index hospitalization, and the 3-month incidence of coronary angiography, percutaneous cardiac intervention, coronary artery bypass surgery, re-presentation to our institution’s ED for chest pain, myocardial infarction, or death were followed. Five hundred nine of 1,195 patients (43%) underwent provocative stress MPI during their index hospitalization; 37% had perfusion defects (predominantly ischemia). Fifty-six of 1,195 patients (4%) underwent cardiac catheterization without stress MPI for their primary diagnostic evaluation. Six hundred thirty of 1,195 patients (53%) had neither MPI or cardiac catheterization during their index hospitalization. During the 3-month follow-up period, patients with a normal stress perfusion study during their index hospitalization had fewer return visits (4%) compared with patients with abnormal perfusion studies (19%), those who underwent catheterization directly (16%), or patients with no initial diagnostic evaluation (15%) (p <0.001). In addition, patients who had a diagnostic evaluation during their index hospitalization had a lower incidence of either acute myocardial infarction (0.9% vs 2.1%) or death (0.4% vs 3.0%, p <0.001) in the 3-month follow-up period. Accordingly, we strongly advocate provocative stress MPI early after presentation for chest pain in all patients with risk factors for coronary artery disease.     

Prospective evaluation of radionuclide angiocardiography for the diagnosis of coronary artery disease

This investigation assesses prospectively the accuracy of rest and exercise radionuclide angiocardiography (RNA) in detecting coronary artery disease (CAD). By retrospective analysis of 496 patients, optimal RNA criteria were determined for the presence or absence of CAD. Multivariate analysis of patients with normal coronary arteries on catheterization provided a formula to predict normal exercise ejection fraction (EF) in a given patient. The presence of CAD was indicated by 1 or more of the following RNA measurements: (1) rest EF < 0.50, (2) exercise EF at least 0.06 less than the predicted value, (3) exercise increase in end-systolic volume > 20 ml, (4) exercise-induced wall motion abnormality. The absence of CAD was indicated by the absence of all 4 criteria. After applying these criteria to 221 consecutive patients, the RNA determinations were compared with the catheterization determinations. Significant CAD was present in 71 % of the patients studied. The sensitivity of the test was 0.87 and the specificity 0.54. Thus, because of its high sensitivity, RNA is of value in screening patients under consideration for cardiac catheterization. No patient with significant left main coronary narrowing and only 4 of 65 patients with 3-vessel disease were misdiagnosed. The poor specificity of the test, however, limits its overall accuracy.     

Prognostic value of the Duke treadmill score in the elderly

OBJECTIVES: The purpose of this study was to test the hypothesis that the Duke treadmill score works less well for risk stratification in patients age 75 years or above. BACKGROUND: Although the Duke treadmill score is generally effective for risk stratification, its prognostic value in the elderly may be limited because they have a higher prevalence of coronary artery disease (CAD), more severe CAD and a lower exercise tolerance. METHODS: The study population consisted of 247 patients age 75 years or above, and the control population consisted of 2,304 patients below 75 years of age. All patients were symptomatic, had undergone exercise thallium testing between 1989 and 1991 and were followed for a median of >6.5 years. The Cox regression model was used to test the association of the Duke score (utilized both as a continuous variable and using previously published risk group cutoffs) with outcomes (cardiac death, nonfatal myocardial infarction [MI], late revascularization). RESULTS: Using the Duke score to risk-stratify the elderly, 26% were in the low risk group, 68% were in the intermediate risk group and 6% were in the high risk groups; seven-year cardiac survival was 86%, 85% and 69%, respectively (p = 0.45). There was also no significant association between these Duke score risk groups and all other outcome end points in the elderly. The Duke score as a continuous variable did not predict cardiac death (p = 0.43) or cardiac death or MI (p = 0.42), but did predict total cardiac events (which included late revascularization) (p = 0.0027). For the control population, more patients (55%) were in the low risk group, and the Duke score (as a continuous variable or in risk groups) was highly predictive of all end points (p = 0.0001). CONCLUSIONS: The Duke score predicted cardiac survival in younger patients but not in patients age 75 years or above. The majority of the elderly were classified as intermediate risk by the Duke score. Only a minority of the elderly were classified as low risk, but this group still had an annual cardiac mortality of 2%/year.     

Role of exercise thallium 201 imaging in decision making

This prospective study examined the impact of results of exercise thallium 201 imaging on the estimation of probability of coronary artery disease (CAD) and patient management among cardiologists and internists in our institution. Before exercise testing, the probability of CAD in the 100 patients enrolled in this study was considered low in 31, intermediate in 28, and high in 41 patients. The probability of CAD after exercise thallium imaging was different in four patients (10%) in the high group, 22 patients (79%) in the intermediate group, and three patients (10%) in the low group. Further, the results of exercise testing resulted in changes in patient management in 29 patients (71%) in the high group, 26 patients (93%) in the intermediate group, and 16 patients (52%) in the low group. Overall, the management changed in 71% of the patients. This change included changes in medications, physical activity, frequency of office visits, need for cardiac catheterization, and need for coronary arterial bypass grafting. Thus, exercise thallium imaging is useful in clinical decision making: the diagnostic certainty is improved in patients with intermediate pretest probability of CAD; and some degree of change in patient management is observed, even in patients in whom the probability of CAD is not altered.     

Stepwise risk stratification soon after acute myocardial infarction

A stepwise rise stratification procedure sequentially combining historical and clinical characteristics and treadmill exercise test results was applied to 702 consecutive men aged ≤70 years who were alive 21 days after acute myocardial infarction (Ml). Historical characteristics alone (prior Ml and prior angina or recurrence of pain in the coronary care unit) identified 10% of patients with the highest rate of reinfarction and death within 6 months (18%). Clinical contraindications to exercise testing identified another 40% of patients with an intermediate rate of cardiac events (6.4%). In the 50% of patients who underwent treadmill testing 3 weeks after Ml, the rate of cardiac events within 6 months was 4.4%: 3.9% in patients with a negative test and 9.7% in patients with a positive test (ischemic ST-segment depression ≥0.2 mV and a peak heart rate ≤135 beats/min). Patients with negative treadmill tests, who comprised 46% of patients ≤70 years and 53% of patients ≤60 years, had a cardiac death rate of <2% in the 6 months after Ml. The stepwise classification procedure correctly classified 72% of patients with hard medical events within 6 months. Thus, most patients who experience subsequent cardiac events are correctly classified on the basis of historical and clinical risk characteristics. In patients without these risk characteristics, early treadmill testing is useful for further discriminating high-risk from very low risk patients.     

Transcatheter vs surgical aortic valve replacement in low to intermediate surgical risk aortic stenosis patients: A systematic review and meta-analysis of randomized controlled trials

BackgroundTranscatheter aortic valve replacement (TAVR) is regarded as the most superior alternative treatment approach for patients with aortic stenosis (AS) who are associated with high surgical risk, whereas the effectiveness of TAVR vs surgical aortic valve replacement (SAVR) in low to intermediate surgical risk patients remained inconclusive. This study aimed to determine the best treatment strategies for AS with low to intermediate surgical risk based on published randomized controlled trials (RCTs).Hypothesis and MethodsRCTs that compared TAVR vs SAVR in AS patients with low to intermediate surgical risk were identified by PubMed, EmBase, and the Cochrane library from inception till April 2019. The pooled relative risks (RRs) with 95% confidence intervals (CIs) were calculated for the data collected using random‐effects models.ResultsSeven RCTs with a total of 6929 AS patients were enrolled. We noted that TAVR significantly increased the risk of transient ischemic attack (TIA) (RR: 1.43; 95%CI: 1.04‐1.96; P = .029), and permanent pacemaker implantation (RR: 3.00; 95%CI: 1.70‐5.30; P < .001). However, TAVR was associated with lower risk of post‐procedural bleeding (RR: 0.57; 95%CI: 0.33‐0.98; P = .042), new‐onset or worsening of atrial fibrillation (RR: 0.32; 95%CI: 0.23‐0.45; P < .001), acute kidney injury (RR: 0.40; 95%CI: 0.25‐0.63; P < .001), and cardiogenic shock (RR: 0.34; 95%CI: 0.19‐0.59; P < .001). The risk of aortic‐valve reintervention at 1‐ (RR: 2.63; 95%CI: 1.34‐5.15; P = .005), and 2 years (RR: 3.19; 95%CI: 1.63‐6.24; P = .001) in low to intermediate surgical risk patients who received TAVR was significantly increased than those who received SAVR.ConclusionsThese findings indicated that low to intermediate surgical risk patients who received TAVR had low risk of complications, whereas the risk of TIA, permanent pacemaker implantation, and aortic‐valve reintervention was increased.     

Guidelines for the management of patients with chronic stable angina: diagnosis and risk stratification

Patients with suspected chronic stable angina can be evaluated in three stages. In stage one, the clinician uses information from the history, physical examination, laboratory tests for diabetes and hyperlipidemia, and resting electrocardiography to estimate the patient's probability of coronary artery disease (CAD). In stage two, additional testing for patients with a low probability of CAD focuses on diagnosing noncoronary causes of chest pain. Patients with a high probability of CAD have stress tests to assess their risk from CAD, and patients with an intermediate probability of CAD have stress tests to estimate the probability of CAD and assess their risk from CAD. Most patients with new-onset angina can start stress testing with exercise electrocardiography. The initial stress test should be a stress imaging procedure for patients with rest ST-segment depression greater than 1 mm, complete left bundle-branch block, ventricular paced rhythm, preexcitation syndrome, or previous revascularization with percutaneous coronary angioplasty or coronary artery bypass grafting. Patients who cannot exercise can have an imaging procedure with stress induced by pharmacologic agents. In stage three, patients with a predicted average annual cardiac mortality rate between 1% and 3% should have a stress imaging study or coronary angiography with left ventriculography. Those with a known left ventricular dysfunction should have cardiac catheterization. Patients with CAD who have an estimated annual mortality rate greater than 3% should have cardiac catheterization to determine whether their anatomy is suitable for revascularization. Patients with an estimated annual mortality rate less than 1% can begin to receive medical therapy.     

The prevalence of cardiac risk factors in women 45 years of age or younger undergoing angiography for evaluation of undiagnosed chest pain

BACKGROUND: Relatively little is known about the prevalence of cardiac risk factors, the use of noninvasive testing and the medical management of younger women (younger than 45 years of age) undergoing evaluation for chest pain. OBJECTIVES: To determine the rate of angiographically critical coronary artery disease (CAD) in women under the age of 45 years who were sent for first-time evaluation of chest pain requiring cardiac catheterization, and to determine the prevalence of cardiac risk factors, the role of noninvasive testing and the quality of medical management in these patients. PATIENTS AND METHODS: A retrospective chart review was performed on all female patients aged 45 years or younger from February 1997 to December 2000 (n=187) without prior known CAD referred for diagnostic cardiac catheterization. Chart information was studied, including catheterization results, cardiac risk factors, noninvasive testing done before catheterization (within six months) and medications at discharge. RESULTS: Angiographically critical CAD was found in 55 of 187 patients (29%), of whom 52% had single-vessel disease. One hundred twenty-one patients (65%) had completely normal coronary arteries. The most prominent cardiac risk factor for all study patients was a family history of premature CAD (67%), followed by smoking (55%) and dyslipidemia (55%). When compared with people without CAD, women with CAD had a higher prevalence of dyslipidemia (72% versus 47%, P=0.002), diabetes (29% versus 9%, P<0.001) and smoking (67% versus 50%, P=0.03). Noninvasive testing including exercise stress testing (calculated sensitivity of 44% and a specificity of 73%), and stress sestamibi scintigraphy (sensitivity of 67%, specificity of 30%) were both found to be poor predictors of those with CAD. Of all patients diagnosed as having critical CAD (n=55), 40% were discharged on an angiotensin-converting enzyme inhibitor, 73% on acetylsalicylic acid and 69% on a beta-blocker. CONCLUSIONS: The present study implies that younger women with CAD may have a higher prevalence of dyslipidemia, diabetes and smoking. The high percentage of women with minimally diseased or normal coronary arteries emphasizes the importance of confirmatory testing and poor use of noninvasive testing. The medical management of young women diagnosed with CAD is seemingly suboptimal, which may have important implications in later years of life.     

Relationship between noninvasive coronary angiography with multi-slice computed tomography and myocardial perfusion imaging.

OBJECTIVES: The aim of this study was to perform a head-to-head comparison between multi-slice computed tomography (MSCT) and myocardial perfusion imaging (MPI) in patients with an intermediate likelihood of coronary artery disease (CAD) and to compare non-invasive findings to invasive coronary angiography. BACKGROUND: Multi-slice computed tomography detects atherosclerosis, whereas MPI detects ischemia; how these 2 techniques compare in patients with an intermediate likelihood of CAD is unknown. METHODS: A total of 114 patients, mainly with intermediate likelihood of CAD, underwent both MSCT and MPI. The MSCT studies were classified as having no CAD, nonobstructive (<50% luminal narrowing) CAD, or obstructive CAD. Myocardial perfusion imaging examinations were classified as showing normal or abnormal (reversible and/or fixed defects). In a subset of 58 patients, invasive coronary angiography was performed. RESULTS: On the basis of the MSCT data, 41 patients (36%) were classified as having no CAD, of whom 90% had normal MPI. A total of 33 patients (29%) showed non-obstructive CAD, whereas at least 1 significant (> or =50% luminal narrowing) lesion was observed in the remaining 40 patients (35%). Only 45% of patients with an abnormal MSCT had abnormal MPI; even in patients with obstructive CAD on MSCT, 50% still had a normal MPI. In the subset of patients undergoing invasive angiography, the agreement with MSCT was excellent (90%). CONCLUSIONS: Myocardial perfusion imaging and MSCT provide different and complementary information on CAD, namely, detection of atherosclerosis versus detection of ischemia. As compared to invasive angiography, MSCT has a high accuracy for detecting CAD in patients with an intermediate likelihood of CAD.     

Stress test criteria used in the conservative arm of the FRISC-II trial underdetects surgical coronary artery disease when applied to patients in the VANQWISH trial

OBJECTIVES: We sought to determine whether the stringent stress test criteria for crossover to cardiac catheterization in the conservative arm of the Fast Revascularization During Instability in Coronary Artery Disease (FRISC-II) trial subjected this strategy to a disadvantage by failing to identify patients with surgical coronary artery disease (CAD). BACKGROUND: In FRISC-II, an invasive strategy provided superior outcomes compared with a conservative strategy for patients with acute coronary syndromes. However, compared with the stress test criteria for crossover to catheterization in the Veterans Affairs Non-Q-Wave Infarction Strategies in Hospital (VANQWISH) trial, the FRISC-II criteria were more restrictive and did not use nuclear imaging or pharmacologic stress testing. METHODS: We analyzed the conservative arm of VANQWISH to identify the prevalence of surgical CAD in those patients who met the VANQWISH, but not FRISC-II, criteria for catheterization. RESULTS: Of 385 VANQWISH patients, 90 (23%) met the FRISC-II criteria for catheterization. Another 98 patients (25%) met only VANQWISH stress test criteria (60 patients by exercise and 38 by pharmacologic nuclear stress testing). Among subjects who underwent predischarge angiography, those meeting only VANQWISH stress test criteria had a high prevalence of surgical CAD (51%), comparable to patients who met FRISC-II criteria (54%, p = 0.805). CONCLUSIONS: The overly stringent risk stratification protocol for conservative-arm patients in FRISC-II could have failed to identify almost as many patients with surgical CAD as it identified. A lower threshold for catheterization in the FRISC-II conservative patients might have improved their outcomes and therefore diminished the putative benefit of an invasive strategy.     

A hypertensive response to exercise is associated with transient ischemic dilation on myocardial perfusion SPECT imaging.

BACKGROUND: A hypertensive response to exercise (HRE) is associated with false-positive stress echocardiograms and myocardial perfusion single photon emission computed tomography (myocardial perfusion imaging [MPI]) defects even in the absence of coronary artery disease (CAD). Transient ischemic dilation (TID) of the left ventricle on stress MPI is a marker of severe CAD and future cardiac events. This study evaluated the association between an HRE and TID. METHODS AND RESULTS: Blinded quantitative TID assessment was performed in 125 patients who had an HRE and a summed stress score (SSS) of less than 4, as well as 125 control patients with an SSS of less than 4 and without an HRE matched for age, gender, and resting systolic blood pressure. Cardiac comorbidities, pretest Framingham risk, and exercise results were recorded. TID was defined as a stress-to-rest volume ratio of 1.22 or greater. An HRE was associated with a high prevalence of TID and significantly more TID than no HRE (25.6% vs 11.2%; odds ratio, 3.00 [95% confidence interval, 1.41-6.38]). TID was more prevalent even in subgroups with a low pretest probability CAD, including those without diabetes mellitus or angina. On conditional logistic regression analysis, an HRE was found to be independently associated with TID after consideration of other clinical and exercise MPI variables (odds ratio, 2.72 [95% confidence interval, 1.01-7.31]). CONCLUSION: An HRE is associated with a high prevalence of TID in patients without other significant perfusion defects, possibly as a result of global subendocardial ischemia induced by the HRE.     

Prevalence of atrial fibrillation dependent on coronary artery status: Insights from the LIFE-Heart Study

BackgroundCoronary artery disease (CAD) is a significant risk factor for atrial fibrillation (AF). Experimental studies demonstrated that atrial ischemia induced by right coronary artery (RCA) stenosis promote AF triggers and development of electro‐anatomical substrate for AF.AimTo analyze the association between AF prevalence and coronary arteries status in the LIFE‐Heart Study.MethodsThis analysis included patients with available coronary catheterization data recruited between 2006 and 2014. Patients with acute myocardial infarction were excluded. CAD was defined as stenosis ≥75%, while coronary artery sclerosis (CAS) was defined as non‐critical plaque(s) <75%.ResultsIn total, 3.458 patients (median age 63 years, 34% women) were included into analysis. AF was diagnosed in 238 (6.7%) patients. There were 681 (19.7%) patients with CAS and 1.411 (40.8%) with CAD (27.5% with single, 32.4% with double, and 40.1% with triple vessel CAD). In multivariable analysis, there was a significant association between prevalent AF and coronary artery status (OR 0.64, 95% CI 0.53‐0.78, P _trend < .001). Similarly, AF risk was lower in patients with higher CAD extent (OR 0.54, 95%CI 0.35‐0.83, P _trend = .005). Compared to single vessel CAD, the risk of AF was lower in double (OR 0.42, 95%CI 0.19‐0.95, P = .037) and triple CAD (OR 0.31, 95%CI 0.13‐0.71, P = .006). Finally, no association was found between AF prevalence and CAD origin among patients with single vessel CAD.ConclusionIn the LIFE‐Heart Study, CAS but not CAD was associated with increased risk of AF.     

Adiponectin gene variants,adiponectin isoforms and cardiometabolic risk in type 2 diabetic patients

Aims/Introduction

The aim of the present study was to examine the associations of rs2241766 (+45T>G), rs1501299 (+276G>T), rs17300539 (−11391G>A) and rs182052 (−10069G>A) in the adiponectin (Ad) gene with adiponectin concentrations, and concomitantly the association of these variants with cardiometabolic risk in type 2 diabetic patients of African ancestry.

Materials and Methods

A cross‐sectional study of 200 patients was carried out. Concentrations of total, high (HMW), middle (MMW) and low (LMW) molecular weight adiponectin isoforms were measured. The four polymorphisms were genotyped.

Results

Decreased values were noted for total Ad in overweight, dyslipidemia and coronary artery disease (CAD), for HMW in overweight and dyslipidemia, for MMW in CAD, for LMW in dyslipidemia and CAD, for the percentage HMW/total in overweight, and for MMW:HMW ratio in patients without hypertriglyceridemic waist (HTGW). Significant associations were noted between total Ad, HMW, and HMW/total Ad and rs182052 under a dominant model (P = 0.04, P = 0.03 and P = 0.04, respectively), and between MMW and rs17300539 (P = 0.006). No significant difference in adiponectin concentrations was noted according to rs2241766 and rs1501299 genotypes. Patients carrying the rs2241766 G allele (TG+GG) had an increased risk of HTGW (odds ratio [OR] 3.1; P = 0.04) and of CAD (OR 3.3; P = 0.01). The odds of having low total adiponectin concentrations (<25th percentile: 3.49 ng/mL) for carrying the rs182052A allele (AA+GA) was: OR 0.40; P = 0.009. The single‐nucleotide polymorphism associated with adiponectin levels was not concomitantly associated with cardiometabolic risk factors.

Conclusions

Adiponectin concentrations and ADIPOQ variants are implicated in the pathophysiological process leading to cardiovascular diseases, but the genetic effects seem to be independent of adiponectin concentrations in our Afro–Caribbean diabetic patients.     

Probabilidade teórica de doença coronária pré- e pós-teste em duas estratégias diagnósticas – Contributo relativo da prova de esforço e da angio-TC cardíaca

IntroductionThe purpose of this study was to assess the change in theoretical probability of coronary artery disease (CAD) in patients with suspected CAD undergoing coronary CT angiography (CCTA) as first line test vs. patients who underwent CCTA after an exercise ECG.MethodsPre- and post-test probabilities of CAD were assessed in 158 patients with suspected CAD undergoing dual-source CCTA as the first-line test (Group A) and in 134 in whom CCTA was performed after an exercise ECG (Group B). Pre-test probabilities were calculated based on age, gender and type of chest pain. Post-test probabilities were calculated according to Bayes’ theorem.ResultsThere were no significant differences between the groups regarding pre-test probability (median 23.5% [13.3-37.8] in group A vs. 20.5% [13.4-34.5] in group B; p=0,479). In group A, the percentage of patients with intermediate likelihood of disease (10-90%) was 90% before testing and 15% after CCTA (p<0,001), while in group B, it was 95% before testing, 87% after exercise ECG (p=NS), and 17% after CCTA (p<0,001).ConclusionUnlike exercise testing, CCTA is able to reclassify the risk in the majority of patients with an intermediate probability of obstructive CAD. The use of CCTA as a first-line diagnostic test for CAD may be beneficial in this setting.