Matthew W. Parker

Diagnostic accuracy of cardiac positron emission tomography versus single photon emission computed tomography for coronary artery disease: a bivariate meta-analysis.

Background—Positron emission tomography (PET) myocardial perfusion imaging (MPI) offers technical benefits compared with single photon emission computed tomography (SPECT) MPI, but there has been no systematic comparison of their diagnostic accuracy for coronary artery disease. We performed a bivariate meta-analysis of the published literature to compare the sensitivity and specificity of PET versus SPECT stress MPI for ≥50% stenosis of any epicardial coronary artery in patients with known or suspected coronary artery disease. Methods and Results—We searched MEDLINE and EMBASE from inception through January 2012 and the references of identified studies for prospective, English language studies that evaluated the sensitivity and specificity of PET and/or SPECT MPI with coronary angiography as the reference standard and reported sufficient data to calculate patient-level true and false positives and negatives. Two investigators independently extracted patient and study characteristics; a third investigator resolved any disagreements. We identified 117 studies, including 108 evaluating SPECT MPI, 4 evaluating PET MPI, and 5 evaluating both modalities. Bivariate meta-analysis demonstrated a significantly higher pooled mean sensitivity with PET (92.6% [95% Confidence Interval, 88.3% to 95.5%]) compared with SPECT (88.3% [95% confidence interval, 86.4% to 90.0%]) (P=0.035). No significant difference in specificity was observed between PET (81.3% [95% confidence interval, 66.6% to 90.4%]) and SPECT (75.8% [95% confidence interval, 72.1% to 79.1%]) (P=0.39). Few studies investigated coronary angiography with PET. Only 5 studies directly compared SPECT and PET. Conclusions—In a meta-analysis of 11,862 patients, PET MPI demonstrated a higher sensitivity for coronary artery disease than SPECT MPI. No difference in specificity was detected in the pooled analysis of PET and SPECT MPI.

Diagnostic Accuracy of Cardiac Positron Emission Tomography Versus Single Photon Emission Computed Tomography for Coronary Artery DiseaseClinical Perspective

Background—Positron emission tomography (PET) myocardial perfusion imaging (MPI) offers technical benefits compared with single photon emission computed tomography (SPECT) MPI, but there has been no systematic comparison of their diagnostic accuracy for coronary artery disease. We performed a bivariate meta-analysis of the published literature to compare the sensitivity and specificity of PET versus SPECT stress MPI for ≥50% stenosis of any epicardial coronary artery in patients with known or suspected coronary artery disease. Methods and Results—We searched MEDLINE and EMBASE from inception through January 2012 and the references of identified studies for prospective, English language studies that evaluated the sensitivity and specificity of PET and/or SPECT MPI with coronary angiography as the reference standard and reported sufficient data to calculate patient-level true and false positives and negatives. Two investigators independently extracted patient and study characteristics; a third investigator resolved any disagreements. We identified 117 studies, including 108 evaluating SPECT MPI, 4 evaluating PET MPI, and 5 evaluating both modalities. Bivariate meta-analysis demonstrated a significantly higher pooled mean sensitivity with PET (92.6% [95% Confidence Interval, 88.3% to 95.5%]) compared with SPECT (88.3% [95% confidence interval, 86.4% to 90.0%]) (P=0.035). No significant difference in specificity was observed between PET (81.3% [95% confidence interval, 66.6% to 90.4%]) and SPECT (75.8% [95% confidence interval, 72.1% to 79.1%]) (P=0.39). Few studies investigated coronary angiography with PET. Only 5 studies directly compared SPECT and PET. Conclusions—In a meta-analysis of 11,862 patients, PET MPI demonstrated a higher sensitivity for coronary artery disease than SPECT MPI. No difference in specificity was detected in the pooled analysis of PET and SPECT MPI.

Prognostic Accuracy of Clinical Prediction Rules for Early Post-Pulmonary Embolism All-Cause Mortality: A Bivariate Meta-analysis

BACKGROUND Studies suggest outpatient treatment or early discharge of patients with acute pulmonary embolism (aPE) is reasonable for those deemed to be at low risk of early mortality. We sought to determine clinical prediction rule accuracy for identifying patients with aPE at low risk for mortality. METHODS We performed a literature search of Medline and Embase from January 2000 to March 2014, along with a manual search of references. We included studies deriving/validating a clinical prediction rule for early post-aPE all-cause mortality and providing mortality data over at least the index aPE hospitalization but ≤ 90 days. A bivariate model was used to pool sensitivity and specificity estimates using a random-effects approach. Traditional random-effects meta-analysis was performed to estimate the weighted proportion of patients deemed at low risk for early mortality and their ORs for death compared with high-risk patients. RESULTS Forty studies (52 cohort-clinical prediction rule analyses) reporting on 11 clinical prediction rules were included. The highest sensitivities were observed with the Global Registry of Acute Coronary Events (0.99, 95% CI = 0.89-1.00), Aujesky 2006 (0.97, 95% CI = 0.95-0.99), simplified Pulmonary Embolism Severity Index (0.92, 95% CI = 0.89-0.94), Pulmonary Embolism Severity Index (0.89, 95% CI = 0.87-0.90), and European Society of Cardiology (0.88, 95% CI = 0.77-0.94) tools, with remaining clinical prediction rule sensitivities ranging from 0.41 to 0.82. Of these five clinical prediction rules with the highest sensitivities, none had a specificity > 0.48. They suggested anywhere from 22% to 45% of patients with aPE were at low risk and that low-risk patients had a 77% to 97% lower odds of death compared with those at high risk. CONCLUSIONS Numerous clinical prediction rules for prognosticating early mortality in patients with aPE are available, but not all demonstrate the high sensitivity needed to reassure clinicians.

Original Research Pulmonary Vascular DiseasePrognostic Accuracy of Clinical Prediction Rules for Early Post-Pulmonary Embolism All-Cause Mortality: A Bivariate Meta-analysis

BACKGROUND Studies suggest outpatient treatment or early discharge of patients with acute pulmonary embolism (aPE) is reasonable for those deemed to be at low risk of early mortality. We sought to determine clinical prediction rule accuracy for identifying patients with aPE at low risk for mortality. METHODS We performed a literature search of Medline and Embase from January 2000 to March 2014, along with a manual search of references. We included studies deriving/validating a clinical prediction rule for early post-aPE all-cause mortality and providing mortality data over at least the index aPE hospitalization but ≤ 90 days. A bivariate model was used to pool sensitivity and specificity estimates using a random-effects approach. Traditional random-effects meta-analysis was performed to estimate the weighted proportion of patients deemed at low risk for early mortality and their ORs for death compared with high-risk patients. RESULTS Forty studies (52 cohort-clinical prediction rule analyses) reporting on 11 clinical prediction rules were included. The highest sensitivities were observed with the Global Registry of Acute Coronary Events (0.99, 95% CI = 0.89-1.00), Aujesky 2006 (0.97, 95% CI = 0.95-0.99), simplified Pulmonary Embolism Severity Index (0.92, 95% CI = 0.89-0.94), Pulmonary Embolism Severity Index (0.89, 95% CI = 0.87-0.90), and European Society of Cardiology (0.88, 95% CI = 0.77-0.94) tools, with remaining clinical prediction rule sensitivities ranging from 0.41 to 0.82. Of these five clinical prediction rules with the highest sensitivities, none had a specificity > 0.48. They suggested anywhere from 22% to 45% of patients with aPE were at low risk and that low-risk patients had a 77% to 97% lower odds of death compared with those at high risk. CONCLUSIONS Numerous clinical prediction rules for prognosticating early mortality in patients with aPE are available, but not all demonstrate the high sensitivity needed to reassure clinicians.

Stress-only SPECT myocardial perfusion imaging: A review

Myocardial perfusion imaging (MPI) has enjoyed considerable success for decades due to its diagnostic accuracy and wealth of prognostic data. Despite this success several limitations such as lengthy protocols and radiation exposure remain. Advancements to address these shortcomings include abbreviated stress-only MPI (SO MPI) protocols, PET and both hardware and software methods to reduce radiation exposure and time. SO MPI has advantages in protocol time and radiation reduction with a wealth of supporting data in terms of diagnostic validity and prognostic value. Newer technologies such as attenuation correction, and advanced camera technologies have enabled SO MPI to be more efficient in reducing the time of acquisition and radiation dose and improving accuracy. This review examines the literature available, regarding accuracy, patient outcomes, implementation strategies, and newer developments associated with SO MPI.

Predictors of an inadequate defibrillation safety margin at ICD implantation: insights from the National Cardiovascular Data Registry.

BACKGROUND Defibrillation testing is often performed to establish effective arrhythmia termination, but predictors and consequences of an inadequate defibrillation safety margin (DSM) remain largely unknown. OBJECTIVES The aims of this study were to develop a simple risk score predictive of an inadequate DSM at implantable cardioverter-defibrillator (ICD) implantation and to examine the association of an inadequate DSM with adverse events. METHODS A total of 132,477 ICD Registry implantations between 2010 and 2012 were analyzed. Using logistic regression models, factors most predictive of an inadequate DSM (defined as the lowest successful energy tested <10 J from maximal device output) were identified, and the association of an inadequate DSM with adverse events was evaluated. RESULTS Inadequate DSMs occurred in 12,397 patients (9.4%). A simple risk score composed of 8 easily identifiable variables characterized patients at high and low risk for an inadequate DSM, including (with assigned points) age <70 years (1 point); male sex (1 point); race: black (4 points), Hispanic (2 points), or other (1 point); New York Heart Association functional class III (1 point) or IV (3 points); no ischemic heart disease (2 points); renal dialysis (3 points); secondary prevention indication (1 point); and ICD type: single-chamber (2 points) or biventricular (1 point) device. An inadequate DSM was associated with greater odds of complications (odds ratio: 1.22; 95% confidence interval: 1.09 to 1.37; p = 0.0006), hospital stay >3 days (odds ratio: 1.24; 95% confidence interval: 1.19 to 1.30; p < 0.0001), and in-hospital mortality (odds ratio: 1.96; 95% confidence interval: 1.63 to 2.36; p < 0.0001). CONCLUSIONS A simple risk score identified ICD recipients at risk for an inadequate DSM. An inadequate DSM was associated with an increased risk for in-hospital adverse events.

Meta-Analysis of Optimal Risk Stratification in Patients >65 Years of Age

This meta-analysis evaluated the optimal noninvasive strategy for cardiac risk assessment of patients >65 years of age with known or suspected coronary artery disease using the available literature. Patients >65 years of age constitute a growing proportion of the population and have higher cardiovascular morbidity and mortality, but an optimal strategy to predict the risk of cardiac events in this group is unknown. A systematic search of MEDLINE was performed for cohort studies of ≥100 patients >65 years old with ≥12 months of follow-up that reported cardiac death and/or nonfatal myocardial infarction after any of stress myocardial perfusion imaging (MPI), stress echocardiography, or exercise tolerance testing (ETT) for known or suspected coronary artery disease. Pooled annualized event rates were calculated for each technique. Summary odds ratios (ORs) between normal and abnormal test results were calculated using a random-effects model. Seventeen studies (MPI 7, stress echocardiography 7, ETT 3) in 13,304 patients (mean age 75.5 years) were included. Abnormal compared to normal stress MPI (OR 11.8, 95% confidence interval [CI] 7.5 to 18.7) and stress echocardiography (OR 3.2, 95% CI 2.6 to 3.9) accurately stratified risk in patients. However, patients with abnormal and normal ETT results had similar cardiac event rates (OR 3.1, 95% CI 0.8 to 11.5). In conclusion, stress imaging with MPI or stress echocardiography effectively stratified risk in patients, whereas ETT alone did not.

Cost-Effectiveness of Ranolazine Added to Standard-of-Care Treatment in Patients With Chronic Stable Angina Pectoris

Ranolazine has been shown to decrease angina pectoris frequency and nitroglycerin consumption. We assessed the cost-effectiveness of ranolazine when added to standard-of-care (SoC) antianginals compared with SoC alone in patients with stable coronary disease experiencing ≥3 attacks/week. A Markov model utilizing a societal perspective, a 1-month cycle length, and a 1-year time horizon was developed to estimate costs (2013 US

Assessment and Management of Atherosclerosis in the Athletic Patient

) and quality-adjusted life years (QALYs) for patients receiving and not receiving ranolazine. Patients entered the model in 1 of the 4 angina frequency health states based upon Seattle Angina Questionnaire angina frequency (SAQAF) scores (100=no; 61 to 99=monthly; 31 to 60=weekly; and 0 to 30=daily angina) and were allowed to transition between states or to death based upon probabilities derived from the Efficacy of Ranolazine in Chronic Angina and other studies. Patients not responding to ranolazine in month 1 (not improving ≥1 SAQAF health state) were assumed to discontinue ranolazine and behave like SoC patients. Ranolazine patients lived a mean of 0.700 QALYs at a cost of

Stress-first Myocardial Perfusion Imaging.

15,661. Those not receiving ranolazine lived 0.659 QALYs and at a cost of