Aman M. Amanullah

Adenosine myocardial perfusion single-photon emission computed tomography in women compared with men: Impact of diabetes mellitus on incremental prognostic value and effect on patient management

OBJECTIVES This study was designed to assess the incremental prognostic value of adenosine stress myocardial perfusion single-photon emission computed tomography (MPS) in women versus men, and to explore the prognostic impact of diabetes mellitus. BACKGROUND Limited data are available regarding the incremental value of adenosine stress MPS for the prediction of cardiac death in women versus men and the impact of diabetes mellitus on post-adenosine MPS outcomes. Of 6,173 consecutive patients who underwent rest thallium-201/adenosine technetium-99m sestamibi MPS, 254 (4.1%) were lost to follow-up, and 586 with early revascularization < or = 60 days after MPS were censored, leaving 2,656 women and 2,677 men. RESULTS Women had significantly smaller adenosine stress, rest, and reversible defects than men. During 27.0 +/- 8.8 month follow-up, cardiac death rates were lower in women than men (2.0%/year vs. 2.7%/year, respectively, p < 0.05). Before and after risk adjustment, cardiac death risk increased significantly in both men and women as a function of MPS results. Multivariable models revealed that MPS results provided incremental prognostic value over pre-scan data for the prediction of cardiac death in both genders. Also, while comparative unadjusted rates of early (< or =60 days post-test) coronary angiography (17% vs. 23%) and revascularization (8% vs. 12%) were significantly lower in women (p < 0.05), after adjusting for MPS, these rates were similar in men and women. Importantly, diabetic women had a significantly greater risk of cardiac death compared with other patients. Also, after risk adjustment, patients with insulin-dependent diabetes mellitus (IDDM) had higher risk of cardiac death for any MPS result than patients with non-insulin-dependent diabetes mellitus. CONCLUSION The findings suggest that adenosine MPS has comparable incremental value for prediction of cardiac death in women and men and that MPS is appropriately influencing subsequent invasive management decisions in both genders. Diabetic women and patients with IDDM appear to have greater risk of cardiac death than other patients for any MPS result.

Comparative ability of myocardial perfusion single-photon emission computed tomography to detect coronary artery disease in patients with and without diabetes mellitus.

BACKGROUND Diabetics generally have more frequent and extensive silent myocardial ischemia than nondiabetics, increasing the importance of noninvasive detection of coronary artery disease (CAD) in this cohort. However, little is known regarding the diagnostic accuracy of myocardial perfusion single-photon emission computed tomography (SPECT) in patients with diabetes. This study was undertaken to compare the diagnostic value of rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion SPECT in patients with and without diabetes. METHODS Of the 203 patients with diabetes and 260 patients without diabetes who underwent dual-isotope myocardial perfusion SPECT with exercise or pharmacologic stress testing, 138 diabetics (12% type 1 diabetics) and 188 nondiabetics had coronary angiography within 6 months of the nuclear test, and 65 diabetics and 72 nondiabetics had a low likelihood (<10%, mean 6% +/- 3% and 6% +/- 3%) of CAD. RESULTS The angiographic data showed that patients with diabetes had less incidence of 1-vessel disease and a higher incidence of 3-vessel/left main artery disease than patients without diabetes (P <.05). The overall sensitivity and specificity, respectively, of SPECT for detecting CAD with the criterion of >/=50% diameter stenosis were 86% (95 of 111) and 56% (15 of 27) in diabetics, 86% (122 of 142) and 46% (21 of 46) in nondiabetics (P = not significant). With the criterion of >/=70% diameter stenosis the corresponding results were 90% (86 of 96) and 50% (21 of 42) in diabetics, and 91% (108 of 119) and 43% (30 of 69) in nondiabetics, respectively (P = not significant). The normalcy rate for low likelihood patients was 89% (58 of 65) in diabetics and 90% (65 of 72) in nondiabetics (P = not significant). The sensitivity and specificity for individual vessel detection were also similar in patients with and without diabetes (P = not significant) except for a lower sensitivity and a higher specificity for detecting left anterior descending coronary artery disease in the diabetic group (P <.05). CONCLUSION Dual-isotope myocardial perfusion SPECT has comparable accuracy for the diagnosis of CAD in diabetic and nondiabetic patients.

Adenosine technetium-99m sestamibi myocardial perfusion SPECT in women: Diagnostic efficacy in detection of coronary artery disease☆

OBJECTIVES This study sought to assess the diagnostic efficacy of adenosine technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography (SPECT) in a consecutive series of female patients. BACKGROUND The utility of adenosine myocardial perfusion SPECT for the detection of coronary artery disease is not well defined in women because most studies have described a predominantly male population with a high prevalence of coronary artery disease. METHODS Of the 201 consecutive female patients in the study group who had undergone adenosine Tc-99m sestamibi myocardial perfusion SPECT, 130 had coronary angiography within 2 months of the nuclear test, and the other 71 had a low likelihood (<10%, mean [+/-SD] 5 +/- 3%) of coronary artery disease. The SPECT protocol used separate acquisition of rest thallium-201 and adenosine Tc-99m sestamibi and was visually analyzed in 20 segments with a semiquantitative five-point scoring system (0=normal; 4=absent uptake). RESULTS The normalcy rate in patients with a low likelihood of coronary artery disease was 93% (66 of 71). Among the catheterized group, the overall sensitivity, specificity and predictive accuracy of adenosine sestamibi SPECT for detecting coronary artery disease (> or = to 50% diameter stenosis) were 93% (87 of 94), 78% (28 of 36) and 88% (115 of 130), respectively. In the 103 patients without a prior myocardial infarction, the sensitivity, specificity and predictive accuracy were 91% (61 of 67), 78% (28 of 36) and 86% (89 of 103), respectively, for detecting > or = to 50% diameter stenosis. Of particular interest, the sensitivity and specificity were as high in patients with nonanginal symptoms (93% and 69%, respectively) as in patients with angina (92% and 83%, respectively, p=NS). The sensitivity and specificity among patients with a relatively low (<25%), intermediate (between 25% and 75%) or high prescan likelihood of coronary artery disease (>75%) were similar: 82% and 82%, 93% and 73%, and 95% and 100%, respectively. The sensitivity and specificity for detecting individual diseased vessels (> or = to 50% diameter stenosis) were, respectively, 76% and 81% for the left anterior descending coronary artery, 44% and 90% for the left circumflex coronary artery and 75% and 77% for the right coronary artery. CONCLUSIONS Adenosine Tc-99m sestamibi SPECT is an efficient protocol with high sensitivity and specificity for the detection of coronary artery disease in women irrespective of presenting symptoms or pretest likelihood of coronary artery disease and a high normalcy rate. These findings are of particular clinical relevance because chest pain, anginal or otherwise, has been shown to be a frequent but a less specific marker for coronary artery disease among female patients.

Identification of severe or extensive coronary artery disease in women by adenosine technetium-99m sestamibi SPECT

To assess the ability of adenosine technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography (SPECT) to identify high-risk women with severe or extensive coronary artery disease (CAD), we studied 130 consecutive women who underwent adenosine sestamibi myocardial perfusion SPECT and catheterization within 2 months. Severe (> or = 50% stenosis of left main coronary artery, > or = 90% stenosis in the proximal left anterior descending or in > or = 2 coronary arteries) or extensive (> or = 70% stenosis in 3 vessels) CAD was present in 54 patients, whereas 76 had no CAD or mild to moderate CAD. Semiquantitative visual SPECT analysis used 20 segments and a 5-point scoring system (0 = normal, 4 = absent uptake). Among the clinical, hemodynamic and nuclear variables analyzed, univariate predictors of severe or extensive CAD included a higher prescan likelihood of CAD, history of myocardial infarction, a higher heart rate at rest, a lower increase in heart rate during adenosine infusion, a higher summed stress score, summed reversibility score, and multivessel scan abnormality. Multivariate logistic analysis of the most predictive clinical (prescan likelihood of CAD), hemodynamic (increase in heart rate during adenosine infusion), and scan variables (summed stress score) revealed summed stress score (chi-square = 32; p <0.0001) and prescan likelihood of CAD (chi-square = 6.4; p <0.05) as the only independent predictors of severe or extensive CAD. Based on these logistic models, we determined the probability for the presence of severe or extensive CAD in patients with low, intermediate, and high prescan likelihood of CAD across the range of values of a summed stress score. This revealed that there were incremental increases in the probability for severe or extensive CAD both as a function of prescan likelihood of CAD and summed stress score. A severely abnormal scan (summed stress score > 8) during adenosine technetium-99m sestamibi myocardial perfusion SPECT had a high sensitivity of 91% and a moderately high specificity of 70% for identifying high-risk women with severe or extensive CAD. These results coupled with the previously defined prognostic significance of these findings suggest this test to be a useful diagnostic tool for the evaluation of CAD in women.

Impact of myocardial perfusion single-photon emission computed tomography on referral to catheterization of the very elderly Is there evidence of gender-related referral bias?

OBJECTIVES This study sought to assess the impact of myocardial perfusion studies on subsequent management in the very elderly with respect to referral to catheterization or revascularization. BACKGROUND The very elderly are a rapidly growing segment of the U.S. population, and myocardial perfusion studies are frequently performed in this patient subset for evaluation of coronary artery disease. METHODS The study utilized 1,006 consecutive patients > or = 80 years old (511 men, 495 women) who underwent stress myocardial perfusion single-photon emission computed tomography (SPECT) using pharmacologic stress (n = 605) or treadmill exercise (n = 401). Referral to catheterization or revascularization within 60 days of the nuclear scan was correlated with clinical and nuclear variables. RESULTS Catheterization and revascularization were performed in 119 and 77 patients, respectively. Stratification of referral rates showed a low rate in normal and mildly abnormal scan categories and significantly higher rates in patients with severely abnormal scan results irrespective of the presenting symptoms or pretest likelihood of coronary artery disease. Multiple logistic regression analysis of clinical and nuclear variables revealed that extent and severity of reversibility by SPECT and the final scan result were the two most powerful predictors of referral to catheterization and revascularization in men and women (catheterization: chi-square 65 and 78; revascularization: chi-square 37 and 68, respectively). Overall, referral rates to catheterization and revascularization were similar in men and women (catheterization: 13% vs. 11%; revascularization: 8% vs. 8%, respectively). However, women with severely abnormal scan results were more frequently referred to catheterization (28% vs. 18%, p < 0.03) and revascularization (21% vs. 12%, p < 0.01) than men. CONCLUSIONS In patients > or = 80 years old, myocardial perfusion SPECT had a significant impact on patient management. The apparent discrepancy in referral rates for interventional management in men and women is unexplained but may be appropriate in light of our previous observations that women with severely abnormal scan results are at increased risk for hard cardiac events than are men with severely abnormal scan results.

Usefulness ef hemodynamic changes during adenosine infusion in predicting the diagnostic accuracy ef adenosine technetium-99m sestamibi single-photon emission computed tomography (SPECT)

Whether adenosine myocardial perfusion single-photon emission computed tomography (SPECT) remains accurate for detecting coronary artery disease (CAD) in the absence of peripheral hemodynamic changes is unknown. To assess the hemodynamic correlates of perfusion defects, we studied 222 consecutive patients (age 71 +/- 11 years) without prior myocardial infarction or revascularization who underwent adenosine technetium (Tc)-99m sestamibi myocardial perfusion SPECT and cardiac catheterization within 6 months of adenosine study. The SPECT protocol used separate acquisition of rest thallium-201 and adenosine Tc-99m sestamibi, which was semiquantitatively analyzed in 20 segments with a visual 5-point scoring system (0 = normal, 4 = absent uptake). The overall sensitivity, specificity, and predictive accuracy of adenosine Tc-99m sestamibi SPECT for detecting significant CAD were 93% (159 of 171), 73% (37 of 51), and 88% (196 of 222), respectively. The study population was grouped into 6 categories as a function of peripheral hemodynamic changes: (1) increase in heart rate by < or = 10 beats/min (n = 135); (2) increase in heart rate by > 10 beats/min (n = 87); (3) decrease in systolic blood pressure by < or = 10 mm Hg (n = 108); (4) decrease in systolic blood pressure by > 10 mm Hg (n = 114); (5) increase in heart rate by < or = 10 beats/min and decrease in systolic blood pressure by < or = 10 mm Hg (n = 72); and (6) increase in heart rate by > 10 beats/min or decrease in systolic blood pressure by > 10 mm Hg (n = 150). The sensitivity, specificity, and predictive accuracy of adenosine sestamibi SPECT were similar in all 6 categories. The prevalence of left main or multivessel CAD and extent of scan abnormality were also similar among all groups. Thus, the diagnostic accuracy of adenosine Tc-99m sestamibi SPECT is high in patients with or without peripheral hemodynamic evidence of adenosine effect.

Comparison of Dobutamine Echocardiography, Dobutamine Sestamibi, and Rest-Redistribution Thallium-201 Single-Photon Emission Computed Tomography for Determining Contractile Reserve and Myocardial Ischemia in Ischemic Cardiomyopathy

Both dobutamine stress echocardiography (DSE) and myocardial perfusion scintigraphy are used to assess myocardial viability. Few studies have compared the data on myocardial viability and ischemia by low and peak dose DSE and myocardial perfusion imaging in the same patients. Fifty-four patients (45 men and 9 women aged 65 +/- 9 years) with ischemic cardiomyopathy (mean ejection fraction 24 +/- 9%) underwent rest 4-hour redistribution thallium-201 single-photon emission computed tomography (SPECT), low and peak dose DSE, and dobutamine sestamibi SPECT. A total of 864 segments were analyzed (16 segments/patient). Wall motion abnormality was present in 796 segments (92%), and contractile reserve during dobutamine infusion was seen in 400 of these segments (50%). Contractile reserve was seen in 331 of 509 hypokinetic segments (65%) and 69 of 287 akinetic/dyskinetic segments (24%) (p <0.001). Contractile reserve was more frequent in segments with normal thallium uptake (64%), reversible thallium defects (42%), or mild to moderate fixed thallium defects (48%) than severely fixed defects (22%) (p <0.05 each). Concordant information about viability by thallium imaging and DSE was obtained in 62% of segments. Dobutamine sestamibi ischemia was seen in 518 of 796 segments (65%) compared with 265 segments (33%) by DSE (p <0.001). Scintigraphic ischemia was noted in 126 of 195 segments (65%) demonstrating biphasic response, 129 of 205 segments (63%) showing sustained improvement, 42 of 70 segments (60%) deteriorating during dobutamine infusion, and 221 of 326 (68%) demonstrating no change (p = NS). Thus, in patients with ischemic cardiomyopathy, contractile reserve is more frequent in hypokinetic segments than akinetic/dyskinetic segments. The number of segments with normal or near-normal thallium uptake or with scintigraphic ischemia is significantly greater than the number of those capable of increasing contractile function or demonstrating an ischemic response during dobutamine echocardiography.

Usefulness of complex atherosclerotic plaque in the ascending aorta and arch for predicting cardiovascular events

T detection of atherosclerotic lesions in the aorta by transesophageal echocardiography (TEE) is a marker of diffuse atherosclerotic disease, often associated with coronary, carotid, and peripheral vascular diseases. The importance of the thoracic aorta as a source of cerebrovascular emboli is recognized. Although few recent studies have ascertained the importance of the ascending aorta and arch in future neurologic events in selected patient subsets, their importance as predictors of cardiac events is not well established. Autopsy studies have shown that atherosclerotic disease of the thoracic aorta has a direct correlation with the degree of coronary artery disease. Few studies have shown that atherosclerotic lesions of the thoracic aorta, as detected by TEE, appear to be markers of significant coronary artery disease in the general population and in the elderly. The association of complex plaques in the ascending aorta and arch and cardiovascular events is not well defined. This study was undertaken to evaluate whether complex and mobile plaque, as detected by TEE in the ascending aorta and arch, can predict cardiovascular events.

Predictors of outcome of medically treated patients with left main/three-vessel coronary artery disease by coronary angiography

This study examined the prognostic value of single-photon emission computed tomography in angiographically high-risk patients with left main and/or 3-vessel coronary artery disease who were treated medically. Multivariable Cox survival analysis revealed the single-photon emission computed tomography score (based on size of perfusion abnormality, multivessel abnormality, left ventricular dilation, and lung uptake) as the only independent predictor of outcome.

Trends, etiologies, and predictors of 90-day readmission after percutaneous ventricular assist device implantation: A national population-based cohort study

Percutaneous ventricular assist devices (pVADs) are indicated to provide hemodynamic support in high‐risk percutaneous interventions and cardiogenic shock. However, there is a paucity of published data regarding the etiologies and predictors of 90‐day readmissions following pVAD use. We studied the data from the US Nationwide Readmissions Database (NRD) for the years 2013 and 2014. Patients with a primary discharge diagnosis of pVAD use were collected by searching the database for International Classification of Diseases, Ninth Revision, Clinical Modification (ICD‐9‐CM) procedural code 37.68 (Impella and TandemHeart devices). Amongst this group, we examined 90‐day readmission rates. Comorbidities as identified by “CM_” variables provided by the NRD were also extracted. The Charlson Comorbidity Index was calculated using appropriate ICD‐9‐CM codes, as a secondary diagnosis. A 2‐level hierarchical logistic regression model was then used to identify predictors of 90‐day readmission following pVAD use. Records from 7074 patients requiring pVAD support during hospitalization showed that 1562 (22%) patients were readmitted within 90 days. Acute decompensated heart failure (22.6%) and acute coronary syndromes (11.2%) were the most common etiologies and heart failure (odds ratio [OR]: 1.39, 95% confidence interval [CI]: 1.17–1.67), chronic obstructive pulmonary disease (OR: 1.26, 95% CI: 1.07–1.49), peripheral vascular disease (OR: 1.305, 95% CI: 1.09–1.56), and discharge into short‐ or long‐term facility (OR: 1.28, 95% CI: 1.08–1.51) were independently associated with an increased risk of 90‐day readmission following pVAD use. This study identifies important etiologies and predictors of short‐term readmission in this high‐risk patient group that can be used for risk stratification, optimizing discharge, and healthcare transition decisions.