Noninvasive Stress Testing Research Articles

Determinants of variations in initial treatment strategies for stable ischemic heart disease.

The ratio of revascularization to medical therapy (referred to herein as the revascularization ratio) for the initial treatment of stable ischemic heart disease varies considerably across hospitals. We conducted a comprehensive study to identify patient, physician and hospital factors associated with variations in the revascularization ratio across 18 cardiac centres in the province of Ontario. We also explored whether clinical outcomes differed between hospitals with high, medium and low ratios. We identified all patients in Ontario who had stable ischemic heart disease documented by index angiography performed between Oct. 1, 2008, and Sept. 30, 2011, at any of the 18 cardiac centres in the province. We classified patients by initial treatment strategy (medical therapy or revascularization). Hospitals were classified into equal tertiles based on their revascularization ratio. The primary outcome was all-cause mortality. Patient follow-up was until Dec. 31, 2012. Hierarchical logistic regression models identified predictors of revascularization. Multivariable Cox proportional hazards models, with a time-varying covariate for actual treatment received, were used to evaluate the impact of the revascularization ratio on clinical outcomes. Variation in revascularization ratios was twofold across the hospitals. Patient factors accounted for 67.4% of the variation in revascularization ratios. Physician and hospital factors were not significantly associated with the variation. Significant patient-level predictors of revascularization were history of smoking, multivessel disease, high-risk findings on noninvasive stress testing and more severe symptoms of angina (v. no symptoms). Treatment at hospitals with a high revascularization ratio was associated with increased mortality compared with treatment at hospitals with a low ratio (hazard ratio 1.12, 95% confidence interval 1.03-1.21). Most of the variation in revascularization ratios across hospitals was warranted, in that it was driven by patient factors. Nonetheless, the variation was associated with potentially important differences in mortality.

Abstract 180: Variation in the Use of Angiography Between Procedural and Non-procedural Cardiologists

Background: Physician specialty is associated with adherence to practice guidelines; clinical activities may influence management approaches when guidelines create equipoise. In a scenario in which either a non-invasive stress test or invasive angiography is appropriate, we hypothesized that cardiologists who perform cardiac procedures would be more likely to recommend an invasive approach compared to non-procedural cardiologists. Methods: We developed a web-based, email survey with a 2-part standardized patient case. The first part described a patient with symptoms suggestive of obstructive coronary artery disease (CAD) the second part described an abnormal exercise treadmill test (ETT) result in that patient. In both parts, the scenario was designed to represent an intermediate likelihood of obstructive CAD. Providers were asked to rate the likelihood of obstructive CAD and choose between angiography and stress testing for that patient; both a secondary stress and angiography would be consistent with guidelines. Cardiologists were classified based on self-report to non-procedural (general, non-invasive, heart failure/transplant, congenital) or procedural (invasive, interventional, electrophysiology and cardiothoracic surgery) practice. Multivariable models were used to determine the association between procedural practice and referral for angiography controlling for provider factors (age, gender, years in practice, practice setting) and estimated likelihood of CAD for that patient. Results: Of the 500 cardiologists who responded, 41.8% were procedural cardiologists. Procedural cardiologists similarly rated the patient as having a high likelihood for CAD (part 1: 38.8% vs 40.9%, p= 0.63; part 2: 81.8% vs 81.1%, p = 0.84) compared to non-procedural cardiologists. Although for a patient with intermediate risk of CAD by symptoms, more procedural cardiologists recommended direct angiography referral (12% vs 5.6%, p <0.01) than non-procedural cardiologists. In multivariable models, procedural practice remained associated with higher direct angiography referral (OR 2.67; 95% CI 1.30, 5.49, p= 0.008). After an intermediate risk ETT result, both groups recommended angiography more often (70.5% vs 68.2% p=0.58) than secondary stress testing. Conclusions: Procedural cardiologists more often referred a patient with symptoms concerning for CAD directly for angiography compared to non-procedural cardiologists. When presented an abnormal stress test, both groups were equally likely to recommend angiography over additional stress testing. Therefore, clinical activities may influence management approaches; procedural cardiologists pursued an invasive approach earlier in the diagnostic pathway. Efforts to understand variation in invasive procedure use should take physician clinical activities into account.

Diagnostic Performance of Coronary CT Angiography and Myocardial Perfusion Imaging in Kidney Transplantation Candidates

ObjectivesThe goal of this study was to compare the diagnostic accuracy of the coronary artery calcium score (CACS), coronary computed tomography angiography (CTA), single-photon emission computed tomography (SPECT), and a combination of these tools in the diagnosis of obstructive coronary artery disease (CAD) in patients with chronic kidney disease referred for cardiac evaluation before kidney transplantation. BackgroundThe optimal method for the detection of obstructive CAD in potential kidney transplant patients has not yet been identified. Previous studies have found that established noninvasive stress tests have low diagnostic accuracy, while the diagnostic performance of coronary CTA remains unknown. MethodsWe prospectively studied 138 patients referred for pre-transplant cardiac evaluation (mean age 54 years; age range 22 to 72 years; 68% male; 43% treated with dialysis). All patients underwent CACS, coronary CTA, SPECT, and invasive coronary angiography. The results of the noninvasive tests were merged into integrated hybrid imaging results: Hybrid (CACS/SPECT) and Hybrid (coronary CTA/SPECT). ResultsThe overall prevalence of obstructive CAD (≥50% reduction in luminal diameter) according to quantitative invasive coronary angiography was 22%. Two-thirds of the patients with obstructive CAD had a stenosis located in a proximal coronary segment. In a patient-level model, the sensitivity and specificity, respectively, for diagnosing obstructive CAD were as follows: CACS (threshold of 400), 67% and 77%; coronary CTA, 93% and 63%; SPECT, 53% and 82%; Hybrid (CACS/SPECT), 33% and 97%; and Hybrid (coronary CTA/SPECT), 67% and 86%. The sensitivity for diagnosing obstructive CAD in a proximal segment was 70% for CACS (threshold 400), 100% for coronary CTA, 60% for SPECT, 40% for Hybrid (CACS/SPECT), and 75% for Hybrid (coronary CTA/SPECT). ConclusionsCoronary CTA is a reliable test with high sensitivity and a high negative predictive value for diagnosing obstructive CAD before kidney transplantation. A noninvasive approach with use of either coronary CTA or a combination of coronary CTA and SPECT to rule out obstructive CAD seems recommendable in kidney transplant candidates. (ACToR-Study: Angiographic CT of Renal Transplantation Candidate–Study; NCT01344434)

Temporal changes in the use and results of exercise echocardiography.

Limited data are available regarding changes over time in referral patterns and outcomes of non-invasive cardiac stress testing. Our aim was to evaluate the temporal changes in the use and results of exercise echocardiography in our area of reference. A total of 12 339 patients referred to our unit for exercise echocardiography between 1997 and 2012 were included. We divided the 16-year period into four quadrennia and evaluated the changes in clinical data, results of the tests, referrals for invasive management and outcomes. We observed a gradual decrease in the frequency of detection of myocardial ischaemia from 35.3% in1997-2000 to 25.4% in 2009-12 (P < 0.001). There was also a progressive increase in the prevalence of cardiovascular risk factors and in the frequency of non-ischaemic chest pain and dyspnoea, while the proportion of patients with prior myocardial infarction and non-interpretable electrocardiograms declined. The rate of referral to coronary angiography within 6 months decreased from 24.8% in 1997-2000 to 19.6% in 2009-12 (P < 0.001), but the rate of coronary revascularization remained almost unchanged (13.1 to 11.7%, P for the trend = 0.16). We also observed a progressive decrease in the 1-year mortality rate from 3.4 to 1% (P < 0.001). Over a 16-year period, there was a gradual decrease in the frequency of myocardial ischaemia among patients referred to our unit for exercise echocardiography, which was parallel to changes in their clinical profile. However, this was not accompanied by a significant reduction in the rate of coronary revascularization.

THE ROLE OF APPROPRIATE USE CRITERIA FOR NON-INVASIVE STRESS TESTING TO DIAGNOSE SUSPECTED CARDIAC ISCHEMIA

Non-invasive stress testing is an important tool to diagnose patients suspected of having coronary disease. However, indications for these tests are broad. In this study, we examined appropriate use criteria and outcomes of stress testing to rule out coronary disease. 70 patients that were seen in

Fasting but not changes of plasma metabolome during oral glucose tolerance tests improves the diagnosis of severe coronary arterial stenosis.

Noninvasive stress tests for the diagnosis of significant coronary arterial stenosis requiring intervention are not perfect. We investigated whether plasma metabolome during the oral glucose tolerance test (OGTT) can improve the diagnosis. A total of 117 subjects with positive stress test results who received coronary angiography were recruited. After excluding subjects with a history of myocardial infarction and subjects who did not receive OGTT, the 18 subjects without significant stenosis were selected as controls. Another 18 age- and sex-matched subjects with significant stenosis were selected as cases. Plasma metabolome from samples obtained in fasting, 30 and 120min after OGTT was measured using liquid chromatography combined with time-of-flight mass spectrometry. We found five metabolites which can identify patients with significant stenosis independent to clinical risk factors, including diabetes, hypertension, hypercholesterolaemia, smoking and history of percutaneous coronary intervention (all P<0·05). The area under the receiver operating characteristic (AUROC) curve of these metabolites was 0·799-0·818 at fasting and 30min after OGTT. The addition of metabolites to clinical factors increases the AUROC (0·616, 95%CI 0·429-0·803 for model with clinical factors only; 0·824, 95%CI 0·689-0·959 for model with four metabolites and clinical factors). The changes of plasma metabolite levels during OGTT did not significantly improve the diagnostic performance. Fasting plasma metabolome, but not change of plasma metabolome during OGTT, can improve the diagnosis of significant stenosis in patients with positive noninvasive stress test results.

Assessment of cardiovascular physiology using magnetic resonance myocardial stress testing reveals impaired contractile reserve in patients with cirrhotic cardiomyopathy

Background Liver cirrhosis has been shown to affect cardiac performance. However cardiac dysfunction may only be revealed under stress conditions. The value of non-invasive stress tests in diagnosing cirrhotic cardiomyopathy is unclear since their ability to detect abnormalities has been inconsistent using different imaging modalities. We sought to investigate the response to pharmacological stimulation with dobutamine in patients with cirrhosis using cardiovascular magnetic resonance. Methods Thirty-six patients and eight controls were studied. Conventional volumetric and myocardial deformation parameter analysis using feature tracking at rest and during low to intermediate dose dobutamine stress were performed. Results Whilst volumetry based parameters were similar between patients and controls at rest, patients had a smaller increase in cardiac output during stress (2.2 l/min vs. 3.8 l/min), p=0.015). Chronotropic response was not different in the two groups (24 bpm vs 25 bpm, p=0.44). Ejection fraction increase was impaired in patients during 10 μg/Kg/min dobutamine as compared to controls (6.9% vs. 16.5%, p=0.007), but not with 20 μg/Kg/min (12.1% vs. 17.6%, p=0.12). This was paralleled by an impaired improvement in circumferential strain with low dose (median percentual increase of 14.4% vs. 30.9%, p=0.03), but not with intermediate dose dobutamine (median percentual increase of 29.4% vs. 33.9%, p=0.54). There was an impaired longitudinal strain increase in patients as compared to controls during low (median percentual increase of 6.6% vs 28.6%, p<0.001) and intermediate dose dobutamine (median percentual increase of 2.6%vs, 12.6% p=0.016). Radial strain response to dobutamine was similar in patients and controls (median percentual increase of 7.7% (-2.4-15.2) vs 13.6% (5.7-26), p=0.11 with10 μg/Kg/min of dobutamine and 4.3% (0.6-8.1) vs 3.1% (-0.2-9.3), p=0.82 with 20 μg/Kg/min of dobutamine). Conclusions Cirrhotic cardiomyopathy is characterized by an impaired cardiac pharmacological response that can be detected with magnetic resonance myocardial stress testing. Deformation analysis parameters may be more sensitive in identifying abnormalities in inotropic response to stress than conventional methods. Funding NA.

Fractional flow reserve and intravascular ultrasound in the assessment of moderate coronary lesions: a comparative study

Objective The aim of this study was to assess intermediate coronary lesions as detected by visual estimation in coronary angiography using two invasive modalities: fractional flow reserve (FFR) and intravascular ultrasound. Background The significance of coronary artery stenosis of intermediate severity can be difficult to determine. The management of intermediate coronary lesions, defined by a diameter stenosis of more than 40% to less than 70%, continues to be a therapeutic dilemma for cardiologists. The two-dimensional representation of the arterial lesion provided by angiography is limited in distinguishing intermediate lesions that require stenting from those that simply need appropriate medical therapy. Patients and methods Thirty patients with intermediate coronary stenosis on coronary angiography were subjected to a noninvasive stress test, either exercise myocardial perfusion imaging or stress echocardiography, and the results were compared with those of intravascular ultrasound and FFR. Results In this study, 30 patients were subjected to FFR measurement. Twelve of 14 patients had an FFR of less than 0.80; reversible ischemia was detected on the stress test. In contrast, only two of 16 patients with an FFR of more than 0.80 had a negative stress test for reversible myocardial ischemia. FFR value has a sensitivity and a specificity of 85.7 and 87.5%, respectively, in predicting the results of a noninvasive stress test, with a positive predictive value and negative predictive value of 85.7 and 87.5%, respectively, with an accuracy of 86.7%. It is also showed that the best cutoff value for the minimal luminal area that is concordant with FFR values is less than 4.5 mm 2 , which has a sensitivity and a specificity of 57.1 and 56.3%, respectively, and positive predictive value of 53.3% and negative predictive value of 60%. Conclusion In patients with coronary stenosis of intermediate severity, FFR appears to be a useful index for assessment of the functional severity of coronary artery stenosis in comparison with a noninvasive stress test and can be used as a guide before coronary revascularization.

Microvascular angina: angina that predominantly affects women

In women receiving evaluation for suspected ischemic symptoms, a "normal" diagnosis is five times more common than it is in men. These women are often labeled as having cardiac syndrome X, also known as microvascular angina (MVA). MVA is defined as angina pectoris caused by abnormalities of the small coronary arteries, and is characterized by effort chest pain and evidence of myocardial ischemia with a non-invasive stress test, although the coronary arteries can appear normal or near normal by angiography. MVA patients are often neglected due to the assumption of a good prognosis. However, MVA has important prognostic implications and a proper diagnosis is necessary in order to relieve the patients' symptoms and improve clinical outcomes. The coronary microvasculature cannot be directly imaged using coronary angiography, due to the small diameter of the vessels; therefore, the coronary microvascular must be assessed functionally. Treatment of MVA initially includes standard anti-ischemic drugs (β-blockers, calcium antagonists, and nitrates), although control of symptoms is often insufficient. In this review, we discuss the pathophysiology, diagnosis, and treatment of MVA.

Assessment of cardiovascular physiology using dobutamine stress cardiovascular magnetic resonance reveals impaired contractile reserve in patients with cirrhotic cardiomyopathy.

BackgroundLiver cirrhosis has been shown to affect cardiac performance. However cardiac dysfunction may only be revealed under stress conditions. The value of non-invasive stress tests in diagnosing cirrhotic cardiomyopathy is unclear. We sought to investigate the response to pharmacological stimulation with dobutamine in patients with cirrhosis using cardiovascular magnetic resonance.MethodsThirty-six patients and eight controls were scanned using a 1.5 T scanner (Siemens Symphony TIM; Siemens, Erlangen, Germany). Conventional volumetric and feature tracking analysis using dedicated software (CMR42; Circle Cardiovascular Imaging Inc, Calgary, Canada and Diogenes MRI; Tomtec; Germany, respectively) were performed at rest and during low to intermediate dose dobutamine stress.ResultsWhilst volumetry based parameters were similar between patients and controls at rest, patients had a smaller increase in cardiac output during stress (p = 0.015). Ejection fraction increase was impaired in patients during 10 μg/kg/min dobutamine as compared to controls (6.9 % vs. 16.5 %, p = 0.007), but not with 20 μg/kg/min (12.1 % vs. 17.6 %, p = 0.12). This was paralleled by an impaired improvement in circumferential strain with low dose (median increase of 14.4 % vs. 30.9 %, p = 0.03), but not with intermediate dose dobutamine (median increase of 29.4 % vs. 33.9 %, p = 0.54). There was an impaired longitudinal strain increase in patients as compared to controls during low (median increase of 6.6 % vs 28.6 %, p < 0.001) and intermediate dose dobutamine (median increase of 2.6%vs, 12.6 % p = 0.016). Radial strain response to dobutamine was similar in patients and controls (p > 0.05).ConclusionCirrhotic cardiomyopathy is characterized by an impaired cardiac pharmacological response that can be detected with magnetic resonance myocardial stress testing. Deformation analysis parameters may be more sensitive in identifying abnormalities in inotropic response to stress than conventional methods.

Congenital coronary artery anomalies silent until geriatric age: non-invasive assessment, angiography tips, and treatment.

Coronary artery anomalies (CAAs) may be discovered more often as incidental findings during the normal diagnostic process for other cardiac diseases or less frequently on the basis of manifestations of myocardial ischemia. The cardiovascular professional may be involved in their angiographic diagnosis, functional assessment and eventual endovascular treatment. A complete angiographic definition is mandatory in order to understand the functional effects and plan any intervention in CAAs: computed tomography and magnetic resonance imaging are useful non-invasive tools to detect three-dimensional morphology of the anomalies and its relationships with contiguous cardiac structures, whereas coronary arteriography remains the gold standard for a definitive anatomic picture. A practical idea of the possible functional significance is mandatory for deciding how to manage CAAs: non-invasive stress tests and in particular the invasive pharmacological stress tests with or without intravascular ultrasound monitoring can assess correctly the functional significance of the most CAAs. Finally, the knowledge of the particular endovascular techniques and material is of paramount importance for achieving technical and clinical success. CAAs represent a complex issue, which rarely involve the cardiovascular professional at different levels. A timely practical knowledge of the main issues regarding CAAs is important in the management of such entities.

2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines.

Preamble 2216 1. Introduction 2217 2. Clinical Risk Factors: Recommendations 2220 3. Approach to Perioperative Cardiac Testing 2221 4. Supplemental Preoperative Evaluation: Recommendations 2221 5. Perioperative Therapy: Recommendations 2224 6. Anesthetic Consideration and Intraoperative Management: Recommendations 2228 7. Surveillance and Management for Perioperative MI: Recommendations 2229 8. Future Research Directions 2230 Appendix 1. Author Relationships With Industry and Other Entities (Relevant) 2237 Appendix 2. Reviewer Relationships With Industry and Other Entities (Relevant) 2239 Appendix 3. Related Recommendations From Other CPGs 2244 References 2230 The American College of Cardiology (ACC) and the American Heart Association (AHA) are committed to the prevention and management of cardiovascular diseases through professional education and research for clinicians, providers, and patients. Since 1980, the ACC and AHA have shared a responsibility to translate scientific evidence into clinical practice guidelines (CPGs) with recommendations to standardize and improve cardiovascular health. These CPGs, based on systematic methods to evaluate and classify evidence, provide a cornerstone of quality …

Abstract 11773: Liver Transplant Candidates: To Stress or Not to Stress?

Background: The prevalence of coronary artery disease (CAD) in patients with end stage liver disease (ESLD) and the incidence of acute coronary syndromes (ACS) post liver transplantation (LT) remain controversial. Current AHA/ACC guidelines recommend non-invasive stress testing (NIST) for risk stratification of LT recipients based on conventional cardiovascular risk factors (CVRF). The aim of our study was to define the role of NIST in the pre-transplant evaluation of ESLD patients. Methods: We retrospectively reviewed the data of 366 patients who were referred to the Cleveland Clinic LT center between the years 2006 and 2008. We collected demographic data, CVRF, NIST, left heart catheterization (LHC) results, incidence of ACS and death. Results: In our study population, the mean age was 56±8 years, 68% were males, 83% Caucasian, 34% diabetic, 36% hypertensive, 22% smokers, 17% had hyperlipidemia, 11% known CAD, and 14% had family history of premature CAD; overall, 70% of the patients had at least 3 CVRF. Mean platelet count was 104±70 k/uL, mean INR 1.4 ±0.4, total cholesterol (TC) 143±45 mg/dL and 42% were on beta blockers (BB). A total of 270 patients underwent NIST with dobutamine stress echocardiography (DSE) or nuclear stress testing. DSE was diagnostic in 76% of the cases and nuclear stress test was performed in 52% of the patients with a non-diagnostic DSE. From the patients with diagnostic NIST, 40 underwent LHC. There were 5 true positive, 22 true negative, 8 false positive, and 5 false negative results giving NIST a negative predictive value of 81%. After a median follow-up of 6.2 years [IQR 3.4 to 6.7], 264 patients were transplanted, 9 patients developed an ACS and only one of them within the first year of LT. ACS was the cause of death in one patient which occurred more than 3 years from LT. All of these patients had a prior negative NIST. There were no ACS in the non-transplanted group. Conclusions: In our ESLD population, NIST had a limited role in the CV risk assessment of LT candidates. This is probably secondary to the low incidence of ACS which could be explained by inherent ESLD factors like thrombocytopenia, low TC, and elevated INR.

Family History as a Risk Factor for Peripheral Arterial Disease

The association of a family history of peripheral arterial disease (PAD) with the presence of PAD is largely unknown. We conducted a case-control study of 2,296 patients with PAD (69 ± 10 years, 64% men) and 4,390 controls (66 ± 11 years, 62% men) identified from noninvasive vascular and stress testing laboratories at Mayo Clinic, Rochester, Minnesota, from October 2006 through June 2012. PAD was defined as an ankle brachial index of ≤ 0.9 at rest and/or after exercise, a history of lower extremity revascularization, or having poorly compressible leg arteries. Controls were patients with normal ankle brachial index or without a history of PAD. Family history of PAD was defined as having at least 1 first-degree relative who had undergone revascularization or stent placement for PAD before the age of 65 years. Logistic regression analyses were used to evaluate whether a family history of PAD was associated with the presence of PAD, independent of conventional risk factors. A family history of PAD was present more often in patients with PAD than in controls, with a resulting odds ratio (OR) of 2.20 (95% confidence interval [CI] 1.82 to 2.67). The association remained significant after adjustment for conventional risk factors (OR 1.97, 95% CI 1.60 to 2.42). The association was stronger in younger subjects (age <68 years; adjusted OR 2.46, 95% CI 1.79 to 3.38) than in older subjects (adjusted OR 1.61, 95% CI 1.22 to 2.12). A greater number of affected relatives with PAD was also associated with greater odds of presence of PAD (adjusted OR 1.86, 95% CI 1.48 to 2.33 and adjusted OR 2.56, 95% CI 1.60 to 4.11 for patients with 1 and ≥ 2 affected relatives with PAD, respectively). In conclusion, individuals with a family history of PAD have nearly double the odds of having PAD relative to those without such a history.

Risk Stratification of Hypertensive Patients Referred for Renal Transplant.

Cardiovascular disease is the leading cause of morbidity and mortality in patients with end-stage renal disease. The 2012 AHA/ACCF guidelines gave only Class 2b recommendations for screening asymptomatic patients for renal transplant listing. In 2007, we adopted an invasive-only approach for assessment of coronary artery disease (CAD, ≥70% stenosis in a major epicardial vessel) in non-diabetics >50 years old on dialysis (n=159) referred for renal transplant. Prevalence of CAD and risk factors were identified. METHODS: Patients underwent coronary angiography after dialysis initiation and prior to transplant. Noninvasive stress testing was not performed routinely. Binary logistic regression was used to identify predictors of CAD. The initial model was fit and respecified by removal of nonsignificant interaction items. RESULTS: Patients were 50.3% male and 64.2% African-American. Mean age was 57 years. Smoking was present in 47.8%, hypertension (HTN) in 98.7%, hyperlipidemia in 47.2%. CAD was found in 20.1% (10.7% 1 vessel, 5.0% 2 vessel, 4.4% 3 vessel). Significant (p<0.05) bivariate predictors of CAD were history of CAD (Odds Ratio (OR)=18.303), history of MI (OR=7.067), hyperlipidemia (OR=3.109) and history of revascularization by PCI or bypass (OR=37.289). With each additional risk factor, odds of a finding CAD increased by 2.017 times (p<0.001). Patients with LVH were less likely to have CAD (OR=0.389). Patients without history of MI, CHF, stroke or CAD were 3.95 times more likely to have no CAD (p<0.001). Among traditional risk factors for CAD (HTN, hyperlipidemia, smoking), only hyperlipidemia was a significant predictor of CAD. Patients with hyperlipidemia were 3.101 times more likely to demonstrate CAD (p=0.008). The predicted probability of CAD in non-diabetics without risk factors other than HTN was 9%. Probability of CAD with one risk factor was 23%; 2 risk factors 47%; 3 risk factors 73% and all 4 risk factors 89%. CONCLUSIONS: In the absence of risk factors, the likelihood of identifying CAD at cardiac cath was very small. Routine cath in hypertensive patients >50 years old being considered for renal transplant without other risk factors for CAD is not warranted. Noninvasive testing should be adequate for most patients with HTN referred for renal transplant, including those > 50 years old.

High-sensitivity cardiac troponin T and copeptin assays to improve diagnostic accuracy of exercise stress test in patients with suspected coronary artery disease

The average diagnostic sensitivity of exercise stress tests (ESTs) is lower than that of other non-invasive cardiac stress tests. The aim of the study was to examine whether high-sensitivity cardiac troponin T (hs-cTnT) or copeptin concentrations rise in response to inducible myocardial ischaemia and may improve the diagnostic accuracy of ESTs. An EST was performed stepwise on a bicycle ergometer by 383 consecutive patients with suspected or progression of coronary artery disease (CAD). In addition venous blood samples for measurement of hs-cTnT and copeptin were collected prior to EST, at peak exercise, and 4 h after EST. Coronary angiography was assessed for all patients. Patients with significant CAD (n = 224) were more likely to be male and older compared to patients with non-significant CAD (n = 169). Positive EST was documented in 125 (55.8%) patients with significant CAD and in 69 (43.4%) patients with non-significant CAD. Copeptin and hs-cTnT concentrations at baseline were higher in patients with significant CAD (copeptin: 10.8 pmol/l (interquartile range (IQR) 8.1-15.6) vs 9.4 pmol/l (IQR 7.1-13.9); p = 0.04; hs-cTnT: 3.0 ng/l (IQR <3.0-5.4) vs <3.0 ng/l (IQR <3.0); p = 0.006). Hs-cTnT improved sensitivity (61.6% vs 55.8%), specificity (67.7% vs 56.6%) and the positive predictive value (PPV) (72.3% vs 64.4%) and negative (55.2% vs 47.6%) predictive value (NPV) of EST. Copeptin could not improve sensitivity (55.4% vs 55.8%) and reduced specificity, PPV and NPV. The measurement of hs-cTnT during EST improves sensitivity, specificity, and positive and negative predictive values. In contrast, measurement of copeptin does not improve diagnostic sensitivity and reduces specificity.

Increased hyperaemic coronary microvascular resistance adds to the presence of myocardial ischaemia.

It has been argued that hyperaemic microvascular resistance (HMR), defined as the ratio of mean distal coronary pressure to flow velocity, is overestimated in the presence of a coronary stenosis compared to actual microvascular resistance (MR), due to neglecting collateral flow. We aimed to test the hypothesis that HMR allows accurate identification of microvascular functional abnormalities by evaluating the association between high or low HMR and the presence of myocardial ischaemia on non-invasive stress testing. Myocardial perfusion scintigraphy was performed in 228 patients, with 299 lesions to identify reversible myocardial ischaemia. Intracoronary distal pressure and flow velocity were assessed during adenosine-induced hyperaemia (20-40 µg, intracoronary) to determine hyperaemic stenosis resistance (HSR) and HMR. HMR >1.9 mmHg/cm/s was defined as high. The diagnostic odds ratio (OR) for myocardial ischaemia for lesions associated with high compared to low HMR was 2.6 (95% confidence interval [CI]: 1.5-4.4; p<0.001) overall, 3.3 (95% CI: 1.2-9.0; p=0.02) for lesions with HSR >0.8 mmHg/cm/s, and 1.3 (95% CI: 0.6-2.9; p=0.52) for lesions with HSR ≤0.8 mmHg/cm/s. The increased risk of myocardial ischaemia in the presence of high HMR, uncorrected for collateral flow, demonstrates that HMR is reflective of an increase in actual MR, identifying pertinent pathophysiological alterations in the microvasculature.

Essentials of noninvasive cardiac stress testing

To provide advanced practice nurses (APNs) with practice recommendations for noninvasive cardiac stress testing (NCST) to enhance diagnostic test selection and to improve the interpretation of the test results. A review and synthesis of current scientific literature on noninvasive cardiac stress tests was conducted including a review of pertinent guidelines, indications, contraindications, procedures and findings of exercise, pharmacological, echocardiographic, and myocardial perfusion imaging studies. Noninvasive cardiac stress testing is an integral component in the care of men and women for the diagnosis, prognosis, and management of individuals at risk for cardiovascular conditions or with known histories of cardiovascular disorders. Cardiovascular disorders are common in our society. APNs care for a variety of individuals in the inpatient and outpatient settings that may require noninvasive cardiac stress tests for the evaluation of significant health histories and clinical presentations. An enhanced understanding of NCST improves test selection, preparation and education of patients, interpretation of test results, and implications for future patient care.

Link between angiographic extent and severity of coronary artery disease and degree of sensorineural hearing loss

Atherosclerosis is a systemic disease that can affect the whole arterial tree. An important cause of neuronal degeneration is atherosclerosis, which may lead to sensorineural hearing loss. We aimed to investigate the relationship between the angiographic severity and extent of coronary artery disease, which is a surrogate of atherosclerotic burden, and the degree of sensorineural hearing loss. Out of 381 consecutive patients who underwent coronary angiography for symptoms suggesting ischemic heart disease and who had ischemia detected by a noninvasive stress test, 265 patients [mean age, 61.5 ± 13.0 years; median age (25th-75th percentile), 59 years (50.5-67)], including 146 male (55.1 %) subjects met the eligibility criteria and were enrolled. Audiological measurements (hearing levels and discrimination scores) were performed before the coronary angiography. The Gensini score was calculated for each angiogram. There was a statistically significant positive correlation between the degree of hearing loss at all frequencies analyzed (250, 500, 1,000, 2,000, 4,000 Hz) and the Gensini score (p < 0.05 for all frequencies), which remained significant after adjustment according to age and other risk factors. A statistically significant negative correlation was observed between the Gensini score and the speech discrimination score (p < 0.05). The findings of this study suggest that the angiographic severity and extent of coronary artery disease are significantly and independently correlated with the degree of hearing loss. Sensorineural hearing loss was more prominent in patients with higher Gensini scores. We propose that the findings of this study warrant further research and should be verified in large-scale studies.

Assessment of the new appropriate use criteria for diagnostic catheterization in the detection of coronary artery disease following noninvasive stress testing

BackgroundAppropriate use criteria (AUC) for diagnostic catheterization (DC) developed by the American College of Cardiology Foundation (ACCF) and other professional societies were recently published. These criteria have yet to be examined thoroughly using existing DC databases. Methods and resultsNew York State's Cardiac Diagnostic Catheterization Database was used to identify patients undergoing DC “for suspected coronary artery disease (CAD)” in 01/2010-06/2011 who underwent noninvasive stress testing. Patients rated for appropriateness using symptoms and stress test results were examined to determine the percentage with obstructive CAD and to explore the benefit of adding Global Risk Score (GRS) to the AUC. Of the 4432 patients who could be rated, 1530 (34.5%) had obstructive CAD, which varied from 22% for patients rated inappropriate to 47% for patients rated appropriate. Of all patients with low risk stress test results/no symptoms, all of whom were rated “inappropriate” for DC, only 8% of those patients with low GRS had obstructive CAD, whereas 44% of the patients with high GRS had obstructive CAD. ConclusionsGlobal Risk Score improved the ability of symptoms and stress test results to identify obstructive CAD in patients with “suspected CAD” with prior stress tests, and it might be helpful to add GRS to the DC AUC for those patients. These findings should be regarded as hypothesis generating unless/until they can be confirmed by other data bases.