Prognostic value of dobutamine stress echocardiography in patients with chronic kidney disease

Resting strain analysis to identify myocardial ischemia in patients with advanced chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is associated with higher incidence of cardiovascular death. Screening for coronary artery disease in asymptomatic or mildly symptomatic patients is challenging.

OBJECTIVE

The aim of this study was to investigate the incremental value of resting deformation analysis in predicting positive results for myocardial ischemia during stress transthoracic echocardiography in patients with end-stage CKD.

METHODS

Sixty-one patients (mean age: 62.3 ± 11.8, 65.7% men) with end-stage CKD were included in the study. Patients underwent a resting transthoracic echocardiogram and a dobutamine stress contrast echo (DSE) protocol. Positive results of DSE were defined as stress-induced left ventricular (LV) wall motion abnormalities.

RESULTS

The study cohort had normal or mildly impaired systolic function: mean LV ejection fraction (EF) was 49.2% (±10.4) and mean LV global longitudinal strain (GLS) was 14.4% (±4.5). Half of our population had impaired left atrial (LA) strain: mean LA reservoir, conduit, and contractile reserve were 24.1% (±12.6), 10.6% (±5.9), and 13.6% (±9.2), respectively. DSE was positive for ischemia in 55.7%. A significant negative association with DSE results was found for LV EF, LV GLS and the conduit phase of LA strain. Both LV and LA dimensions showed positive correlation with presence of ischemia in DSE. Multivariate logistic regression analysis showed that LV GLS was independently associated with DSE (p = 0.007), after controlling for covariates, with high diagnostic accuracy.

CONCLUSION

Resting LV deformation could predict positive results during DSE, thus may be useful to better identify renal patients who might benefit from coronary artery screening.

Safety, accuracy, and prediction of prognosis in patients with end-stage chronic kidney disease undergoing dobutamine stress cardiac magnetic resonance imaging

Introduction

Advanced chronic kidney disease (CKD) is an independent risk factor for coronary artery disease (CAD). Due to its unique uremia-derived pathophysiology of atherosclerosis and the limitations of using potentially harmful contrast agents, the best non-invasive approach to assess CAD in these patients remains unclear. We sought to investigate the accuracy, safety, and prognosis of patients with severe CKD undergoing dobutamine stress cardiac magnetic resonance imaging (CMR).

Materials and methods

In this retrospective, single-center study, patients on dialysis or with a glomerular filtration rate of <15 ml/min/1.73 m2 who underwent dobutamine stress CMR were included. A rest and stress wall motion analysis was performed using dobutamine/atropine as stressor. The target heart rate was 85% of the maximum heart rate. Periprocedural adverse events and 1-year follow-up data were obtained.

Results

A total of 176 patients (127 men, 49 women) with a mean age of 60.9 ± 14.7 years were included, of which 156 patients were on permanent dialysis. Short-term symptoms such as angina or shortness of breath during stress CMR were frequent (22.1%), but major complications were rare (one patient with myocardial infarction, 0.6%). The 1-year event rate was high (16.4%) with a significant independent correlation to reduced ejection fraction at rest (p = 0.037) and failure to achieve the target heart rate (p = 0.029). The overall accuracy for predicting significant CAD was good (sensitivity of 71.4%, specificity of 98.4%) and excellent if the target heart rate was achieved (83.3%, 97.9%). A negative stress CMR was highly predictive for the absence of major adverse cardiac event or any coronary revascularization during the 1-year follow-up (negative predictive value of 95.0%).

Discussion

Dobutamine stress CMR is a safe and accurate diagnostic imaging technique in patients at advanced stages of chronic kidney disease. A reduced ejection fraction and the inability to reach the target heart rate are independent predictors of a poor outcome.

Prognostic implication of myocardial perfusion and contractile reserve in end-stage renal disease: A direct comparison of myocardial perfusion scintigraphy and dobutamine stress echocardiography

BACKGROUND

We aimed to compare the prognostic value of myocardial perfusion scintigraphy (MPS) and dobutamine stress echocardiography (DSE) in patients with end-stage renal disease (ESRD) without known coronary artery disease.

METHODS

Two-hundred twenty-nine ESRD patients who applied for kidney transplantation at our centre were prospectively evaluated by MPS and DSE. The primary endpoint was a composite of myocardial infarction (MI) or all-cause mortality. The secondary endpoint included MI or coronary revascularization (CR) not triggered by MPS or DSE at baseline.

RESULTS

MPS detected reversible ischemia in 31 patients (13.5%) and fixed perfusion defects in 13 (5.7%) patients. DSE discovered stress-induced wall motion abnormalities (WMAs) in 28 (12.2%) and at rest in 18 (7.9%) patients. MPS and DSE results agreed in 85.6% regarding reversible defects (κ = 0.358; P < .001) and in 90.8% regarding fixed defects (κ = 0.275; P < .001). Coronary angiography detected relevant stenosis > 50% in only 15 of 38 patients (39.5%) with pathological findings in MPS and/or DSE. At a median follow-up of 8 years and 10 months, the primary endpoint occurred in 70 patients (30.6%) and the secondary endpoint in 24 patients (10.5%). The adjusted Cox hazard ratios (HRs) for the primary endpoint were 1.77 (95% CI 1.02-3.08; P = .043) for perfusion defects in MPS and 1.36 (95% CI 0.78-2.37; P = ns) for WMA in DSE. The secondary endpoint was significantly correlated with the findings of both modalities, MPS (HR 3.21; 95% CI 1.35-7.61; P = .008) and DSE (HR 2.67; 95% CI 1.15-6.20; P = .022).

CONCLUSION

Perfusion defects in MPS are a stronger determinant of all-cause mortality, MI and the need for future CR compared with WMAs in DSE. Given the complementary functional information provided by MPS vs DSE, results are sometimes contradictory, which may indicate differences in the underlying pathophysiology.

Cardiac imaging for the assessment of patients being evaluated for kidney transplantation

Cardiac risk assessment before kidney transplantation has become widely accepted. However, the optimal patient selection and screening tool for cardiac assessment remain controversial. Clinicians face several challenges in this process, including the ever-growing pre-transplant population, aging transplant candidates, increasing prevalence of coronary artery disease, and scarcity of donor organs. Optimizing the cardiovascular risk profile in kidney transplant candidates is necessary to better appropriate limited donor organs and improve patient outcomes. Increasing waiting times from the initial evaluation for transplant candidacy to the actual transplant raises questions regarding re-testing and re-stratification of risk. In this review, we summarize and discuss the current literature on cardiac evaluation prior to kidney transplantation. We also propose simple evidence-based evaluation algorithms for initial and follow-up CAD surveillance in patients being wait-listed for kidney transplantation.

Chronic Renal Failure and Cardiovascular Disease: A Comprehensive Appraisal

Coronary artery disease is highly prevalent in patients with chronic kidney disease. The concomitant renal disease often poses a major challenge in decision making as symptoms, cardiac biomarkers and noninvasive studies for evaluation of myocardial ischemia have different sensitivity and specificity thresholds in this specific population. Moreover, the effectiveness and safety of intervention and medical treatment in those patients is of great doubt as most clinical studies exclude patients with advance CKD. In the present paper, we discuss and review the literature in the diagnosis, treatment and prevention of CAD in the acute and chronic setting, in patients with CKD.

Coronary Artery Disease in Chronic Kidney Disease: Need for a Heart-Kidney Team-Based Approach

Chronic kidney disease and coronary artery disease are co-prevalent conditions with unique epidemiological and pathophysiological features, that culminate in high rates of major adverse cardiovascular outcomes, including all-cause mortality. This review outlines a summary of the literature, and nuances pertaining to non-invasive risk assessment of this population, medical management options for coronary heart disease and coronary revascularisation. A collaborative heart-kidney team-based approach is imperative for critical management decisions for this patient population, especially coronary revascularisation; this review outlines specific periprocedural considerations pertaining to coronary revascularisation, and provides a proposed algorithm for approaching revascularisation choices in patients with end-stage kidney disease based on available literature.

Preoperative Cardiovascular Assessment of the Renal Transplant Recipient: A Narrative Review

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

Cardiovascular evaluation in advanced chronic kidney disease

Patients with chronic kidney disease (CKD) display an increased cardiovascular comorbidity, which is often underdiagnosed. Thus, effective cardiovascular diagnostic testing is of particular importance for this group of patients. Data from prospective randomized trials with cardiovascular diagnostic testing in CKD patients and improved outcome are limited. Diagnostic stress testing for CKD patients requires special consideration. Guidelines recommend cardiovascular diagnostic testing for patients undergoing an evaluation before transplantation.

[Cardiovascular diagnostic testing in advanced chronic kidney disease: which tests are useful?]

Against the background of drastically increased cardiovascular comorbidity in patients with chronic kidney disease (CKD), an effective cardiovascular diagnostic approach appears essential. However, patients with CKD are often underdiagnosed. Prospective randomized studies showing an improved outcome for cardiovascular diagnostic in patients with CKD are limited. Special attention is paid to stress diagnostics in CKD patients. Guidelines recommend cardiovascular diagnostic evaluation prior to inclusion on the transplantation waiting list.

The assessment of coronary artery disease in patients with end-stage renal disease

Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality among patients with end-stage renal disease (ESRD). Clustering of traditional atherosclerotic and non-traditional risk factors drive the excess rates of coronary and non-coronary CVD in patients with ESRD. Coronary artery disease (CAD) is a key disease process, present in ∼50% of the haemodialysis population ≥65 years of age. Patients with ESRD are more likely to be asymptomatic, posing a challenge to the correct identification of CAD, which is essential for appropriate risk stratification and management. Given the lack of randomized clinical trial evidence in this population, current practice is informed by observational data with a significant potential for bias. For this reason, the most appropriate approach to the investigation of CAD is the subject of considerable discussion, with practice patterns largely varying between different centres. Traditional imaging modalities are limited in their diagnostic accuracy and prognostic value for cardiac events and survival in patients with ESRD, demonstrated by the large number of adverse cardiac outcomes among patients with negative test results. This review focuses on the current understanding of CAD screening in the ESRD population, discussing the available evidence for the use of various imaging techniques to refine risk prediction, with an emphasis on their strengths and limitations.

Cardiac risk assessment for end-stage renal disease patients on the renal transplant waiting list

Cardiovascular disease is a leading cause of morbidity and mortality and is becoming more prevalent as the population ages and risk factors increase. This is most apparent in the end-stage renal disease (ESRD) patient population. In part, this is due to cofactors such as diabetes and hypertension commonly predisposing to progressive renal disease, as well as being a direct consequence of having renal failure. Of all major organ failures, kidney failure is the most likely to be managed chronically using renal replacement therapy and, ultimately, transplant. However, lack of transplant organs and a large renal failure cohort means waiting lists are often quite long and may extend to 5-10 years. Due to the cardiac risk factors inherent in patients awaiting transplant, many succumb to cardiac issues while waiting and present an increased per-procedural cardiac risk that extends into the post-transplant period. We aim to review the epidemiology of coronary artery disease in this population and the etiology as it relates to ESRD and its associated co-factors. We also will review the current approaches, recommendations and evidence for management of these patients as it relates to transplant waiting lists before and after the surgery. Recommendations on how to best manage patients in this cohort revolve around the available evidence and are best customized to the institution and the structure of the program. It is not clear whether the revascularization of patients without symptoms and with a good functional status yields any improvement in outcomes. Therefore, each individual case should be considered based on the risk factors, symptoms and functional status, and approached as part of a multi-disciplinary assessment program.

Risk Stratification and Treatment of Coronary Disease in Chronic Kidney Disease and End-Stage Kidney Disease

Patients with advanced chronic kidney disease have an enormous burden of cardiovascular morbidity and mortality, but, paradoxically, their representation in randomized trials for the evaluation and management of coronary artery disease has been limited. Clinicians therefore are faced with the conundrum of synergizing evidence from observational studies, expert opinion, and extrapolation from the general population to provide care to this complex and clinically distinct patient population. In this review, we address clinical risk stratification of patients with chronic kidney disease and end-stage kidney disease using traditional cardiovascular risk factors, noninvasive functional and structural cardiac imaging, invasive coronary angiography, and cardiovascular biomarkers. We highlight the unique characteristics of this population, including the high competing risk of all-cause mortality relative to the risk of major adverse cardiac events, likely owing to important contributions from nonatherosclerotic mechanisms. We further discuss the management of coronary artery disease in patients with chronic kidney disease and end-stage kidney disease, including evidence pertaining to medical management, coronary revascularization with percutaneous coronary intervention, and coronary artery bypass grafting. Our discussion includes considerations of drug-eluting versus bare metal stents for percutaneous coronary intervention and off-pump versus on-pump coronary artery bypass graft surgery. Finally, we address currently ongoing randomized trials, from which clinicians are optimistic about receiving guidance regarding the best strategies to incorporate into their practice for the evaluation and management of coronary artery disease in this high-risk population.

Cardiac Imaging in Chronic Kidney Disease Patients

Cardiovascular disease is highly prevalent and it is associated with high morbidity and mortality rates in patients with chronic kidney disease (CKD). The implementation of various imaging modalities may help to risk stratify these patients with a potential ease on the burden of complications and the rising costs of care. In this article we review some of the modern imaging techniques to diagnose cardiac disease in patients affected by CKD.

Echocardiographic assessment in patients with chronic kidney disease: Current update

Patients with chronic kidney disease (CKD) carry a high cardiovascular risk. An abundance of evidence has emerged in recent years establishing minor reductions in estimated glomerular filtration rate as an independent risk factor for cardiovascular mortality. Additionally, cardiac changes, such as left ventricular hypertrophy and impaired left ventricular systolic function, have been associated with an unfavorable prognosis. Despite the significant prevalence of underlying cardiac abnormalities, symptoms may not manifest in many patients with CKD. A range of available and emerging echocardiographic modalities may assist with diagnosing heart disease in CKD. Furthermore, some of these emerging techniques can give an important insight into the pathophysiology of subclinical dysfunction in CKD. This review discusses how current and emerging echocardiographic modalities such as speckle tracking echocardiography and 3D echocardiography might help cardiologists in providing important information to help with diagnosis and risk stratification of cardiac-related morbidity and mortality in patients with renal disease, as well applicability of these tools to current clinical practice.

Screening and risk stratification of coronary artery disease in end-stage renal disease

End-stage renal disease (ESRD) is a growing global health problem with major health and economic implications. Cardiovascular complication is the major cause of morbidity and mortality in this population. Clustering of traditional atherosclerotic risk factors, such as diabetes, systemic inflammation, and altered mineral metabolism, contributes to enhanced systemic atherosclerosis in patients with ESRD. Prevalence of obstructive coronary artery disease (CAD) on coronary angiography exceeds 50% in this population. Despite having extensive CAD and vascular disease, patients with ESRD often do not present with classic symptoms because of impaired exercise capacity and diabetes. Furthermore, clinical trial data are exceedingly lacking in this population, resulting in considerable clinical equipoise regarding the optimal approach to the identification and subsequent management of CAD in these patients. Traditional clinical screening tools, including conventional risk prediction models, are significantly limited in their predictive accuracy for cardiovascular events in patients with ESRD. Noninvasive cardiac stress imaging modalities, such as nuclear perfusion and echocardiography, have been shown to improve the traditional clinical model in identifying the presence of CAD. Furthermore, they add incremental prognostic information to angiographic data. Novel imaging techniques and biomarker assays hold significant promise in further improving the ability to identify and risk-stratify for CAD. This review focuses on the current understanding of the clinical risk profile of asymptomatic patients with ESRD with an emphasis on the strengths and limitations of various noninvasive cardiovascular imaging modalities, including the role of novel methods in refining risk prediction. In addition, issues and challenges pertaining to the optimal timing of initial risk assessment ("screening") and possible repeat screening ("surveillance") are addressed. We also summarize the current data on the approach to the patient with ESRD being evaluated for transplantation in the context of recent guidelines and position statements by various professional societies.

Prognostic value of cardiac tests in potential kidney transplant recipients: a systematic review

BACKGROUND

Whether abnormal myocardial perfusion scintigraphy (MPS), dobutamine stress echocardiography (DSE) or coronary angiography, performed during preoperative evaluation for potential kidney transplant recipients, predicts future cardiovascular morbidity is unclear. We assessed test performance for predicting all-cause mortality, cardiovascular mortality and major adverse cardiac events (MACE).

METHODS

We searched MEDLINE and EMBASE (to February 2014), appraised studies, and calculated risk differences and relative risk ratios (RRR) with 95% confidence intervals (95% CI) using random effects meta-analysis.

RESULTS

Fifty-two studies (7401 participants) contributed data to the meta-analysis. Among the different tests, similar numbers of patients experienced MACE after an abnormal test result compared with a normal result (risk difference: MPS 20 per 100 patients tested [95% CI, 0.11-0.29], DSE 24 [95% CI, 0.10-0.38], and coronary angiography 20 [95% CI, 0.08-0.32; P = 0.91]). Although there was some evidence that coronary angiography was better at predicting all-cause mortality than MPS (RRR, 0.69; 95% CI, 0.49-0.96; P = 0.03) and DSE (RRR, 0.72; 95% CI, 0.50-1.02; P = 0.06), noninvasive tests were as good as coronary angiography at predicting cardiovascular mortality (RRR, MPS, 0.89; 95% CI, 0.38-2.10; P = 0.78; DSE, 1.09; 95% CI, 0.12-10.05; P = 0.93), and MACE (RRR: MPS, 1.09; 95% CI, 0.64-1.86; P = 0.74; DSE, 1.56; 95% CI, 0.71-3.45; P = 0.25).

CONCLUSIONS

Noninvasive tests are as good as coronary angiography at predicting future adverse cardiovascular events in advanced chronic kidney disease. However, a substantial number of people with negative test results go on to experience adverse cardiac events.

Cardiac imaging for the assessment of patients being evaluated for kidney or liver transplantation

Cardiac risk assessment prior to kidney and liver transplantation is controversial. Given the paucity of available organs, selecting appropriate recipients with favorable short- and long-term cardiovascular risk profile is crucial. Using noninvasive cardiac imaging tools to guide cardiovascular risk assessment and management can also be challenging and controversial. In this article, we address the burden of coronary artery disease among kidney and liver transplant candidates and review the literature pertaining to the diagnostic accuracy and the prognostic value of noninvasive cardiac imaging techniques in this population.

Cardiac imaging in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) carry a high cardiovascular risk. In this patient group, cardiac structure and function are frequently abnormal and 74% of patients with CKD stage 5 have left ventricular hypertrophy (LVH) at the initiation of renal replacement therapy. Cardiac changes, such as LVH and impaired left ventricular systolic function, have been associated with an unfavourable prognosis. Despite the prevalence of underlying cardiac abnormalities, symptoms may not manifest in many patients. Fortunately, a range of available and emerging cardiac imaging tools may assist with diagnosing and stratifying the risk and severity of heart disease in patients with CKD. Moreover, many of these techniques provide a better understanding of the pathophysiology of cardiac abnormalities in patients with renal disease. Knowledge of the currently available cardiac imaging modalities might help nephrologists to choose the most appropriate investigative tool based on individual patient circumstances. This Review describes established and emerging cardiac imaging modalities in this context, and compares their use in CKD patients with their use in the general population.

Safety and feasibility of dobutamine stress cardiac magnetic resonance for cardiovascular assessment prior to renal transplantation

AIMS

Current guidelines recommend cardiovascular risk assessment prior to renal transplantation. There is currently no evidence for the role of cardiovascular magnetic resonance (CMR) in this population, despite an established evidence base in the non-chronic kidney disease (CKD) population. Our aim is to determine the feasibility and safety of dobutamine stress CMR (DSCMR) imaging in the risk stratification of CKD patients awaiting renal transplantation.

METHODS

CKD patients who were deemed at high risk for coronary artery disease (CAD) and awaiting renal transplantation underwent DSCMR.

RESULTS

Forty-one patients whose median age was 56 years (range 28–73 years) underwent DSCMR. Nineteen were undergoing haemodialysis, 10 peritoneal dialysis and 12 pre-dialysis. The aetiology of the renal failure was diabetes mellitus in 29%, glomerulonephritis in 24%, hypertension in 22% and autosomal dominant polycystic kidney disease in 10%. Thirty-eight patients (93%) achieved the end point, either positive for ischaemia or negative, achieving at least 85% of age-predicted heart rate. Two of them did not achieve target heart rate and one was discontinued because of severe headache. Of the 38 patients who achieved the end point, 35 (92%) were negative for inducible wall motion abnormalities and four (10%) were positive. There were no serious adverse effects.

CONCLUSION

DSCMR is a well tolerated and viable investigation for the cardiovascular risk stratification of high-risk CKD patients prior to renal transplantation. DSCMR already has an established evidence base in the non-CKD population with superiority over other noninvasive techniques. Larger studies with outcome data are now required to define its true utility in the CKD population.

Myocardial Ischemia Assessment in Chronic Kidney Disease: Challenges and Pitfalls

Coronary artery disease is the leading cause of mortality and morbidity in the chronic kidney disease (CKD) population and often presents with atypical symptoms. Current diagnostic investigations of myocardial ischemia in CKD lack sensitivity and specificity or may have adverse effects. We present a case vignette and explore the challenges of diagnostic myocardial stress investigation in patients with CKD.

Cardiovascular risk assessment in kidney transplantation

Cardiovascular disease (CVD) remains the most common cause of death after kidney transplantation worldwide, with the highest event rate in the early postoperative period. In an attempt to address this issue, screening for CVD prior to transplant is common, but the clinical utility of screening asymptomatic transplant candidates remains unclear. A large degree of variation exists among both transplant center practice patterns and clinical practice guidelines regarding who should be screened, and opinions are based on mixed observational data with great potential for bias. In this review, we discuss the potential risks, benefits, and evidence for screening for CVD in kidney transplant candidates, and also the next steps to better evaluate and treat asymptomatic kidney transplant candidates.

Myocardial microvascular disease and major adverse cardiovascular events in patients with end-stage renal disease: rationale and design of the MICROCARD study

BACKGROUND

Myocardial ischaemia, a consequence of coronary artery disease, is a major cause of death in patients with end-stage renal disease (ESRD). The pathophysiology and clinical presentation of coronary artery disease in ESRD patients seem to differ from non-ESRD patients with higher implication of myocardial microvascular disease (MMD), higher mortality, fewer myocardial infarctions, less significant coronary stenosis and low efficacy of well-established drugs such as statin and angiotensin-converting enzyme inhibitors. No study has investigated the presence of MMD and its clinical impact in ESRD patients.

METHODS

We designed an observational prospective cohort study to investigate the prevalence of MMD and its association with major adverse cardiovascular events (MACE) in ESRD patients with a positive non-invasive test for myocardial ischaemia. Patients eligible for inclusion are those>18 years old receiving dialysis and/or undergoing investigation for kidney transplantation, who are referred to our renal clinic and meet all the inclusion criteria but none of the exclusion criteria. Patients with a positive test for myocardial ischaemia will be enrolled in the 'invasive group'. They will be further examined to detect simultaneously epicardial coronary stenosis by coronary angiography and MMD using pressure wire measurement of fractional flow reserve and coronary flow reserve followed by calculation of the index of microcirculatory resistance. Patients with a negative test for myocardial ischaemia will be enrolled in a 'control group' designed to verify whether the invasive group is indeed at high risk for MACE. Both groups will be followed up for 2 years to compare the incidence of MACE.

CONCLUSION

The MICROCARD study will phenotype MMD and will investigate its relation with the incidence of MACE in ESRD patients with myocardial ischaemia. Clinicaltrial.gov NCT01291771.

Should we screen for coronary artery disease in asymptomatic chronic dialysis patients?

The hemodialysis population is characterized by a high prevalence of 'asymptomatic' coronary artery disease (CAD), which should be interpreted differently from asymptomatic disease in the general population. A hemodynamically significant stenosis may not become clinically apparent owing to impaired exercise tolerance and autonomic neuropathy. The continuous presence of silent ischemia may cause heart failure, arrhythmias, and sudden death. Whether revascularization of an asymptomatic dialysis patient improves outcome remains a moot point, although several observational studies and one small RCT suggest a benefit. It can therefore be defended to screen asymptomatic dialysis patients for CAD. A number of noninvasive screening tests are available, but none has proved equally practical and reliable in the dialysis population as in the general population. Myocardial perfusion scintigraphy (MPS) before and after a pharmacological stress such as dipyridamole can reveal both ischemia and myocardial scarring. When compared with coronary angiography, low sensitivities were reported and attributed to impaired vasodilation to dipyridamole in dialysis patients. A more likely explanation is that not every anatomical stenosis will lead to impaired coronary blood flow on MPS. Numerous studies have shown an incremental prognostic value of dipyridamole-MPS over clinical data for prediction of adverse cardiac events, in some studies even over coronary angiography. Pending the availability of high-quality evidence, in our opinion asymptomatic dialysis patients could undergo dipyridamole-MPS, followed by coronary angiography in case of an abnormal scan. This combined physiological and anatomical evaluation of the coronary circulation allows us to determine which coronary stenosis is clinically relevant and therefore should be revascularized.

Screening for cardiovascular disease in patients with advanced chronic kidney disease

Cardiovascular disease remains the major cause of mortality and morbidity in patients with advanced chronic kidney disease (CKD) and after renal transplantation. The mechanisms for cardiotoxicity are multiple. Identifying high-risk patients remains a challenge. Given, the poor long-term outcome of dialysis patients who do not receive renal transplantation and the lower supply of donor kidneys relative to demand, optimal selection of renal transplantation candidates is crucial. This requires a clear understanding of the validity of cardiac tests in this patient group. This paper explores the strengths and weaknesses of currently available diagnostic tools in patients with advanced CKD. Echocardiography is very useful for the detection of cardiomyopathy and prognosis. Stress echocardiography, myocardial perfusion imaging and coronary angiography are the best tools for the assessment of coronary artery disease. All predict outcome. No single gold standard investigation exists. At present, there is not an optimal technique for predicting sudden cardiac death in this patient group. Ultimately, the choice of cardiac test will always be determined by patient preference, local expertise and availability.

A preoperative echocardiographic predictive model for assessment of cardiovascular outcome after renal transplantation

OBJECTIVE

Major adverse cardiac events (MACE) frequently determine the outcome of renal transplantation (RT). Stress testing is advocated for preoperative risk assessment, but limited information is available on the prognostic value of these tests. We aimed to retrospectively assess the value of preoperative dobutamine stress echocardiography (DSE) in predicting MACE in patients undergoing RT.

METHODS

A total of 185 patients (age 56 +/- 11 years, 64% were men, creatinine level of 7.3 +/- 2.9 mg/d, 27% were smokers, 86% had hypertension, 54% had diabetes, 57% were dyslipidemic) with end-stage renal disease (ESRD) underwent DSE before RT. A standard DSE protocol was used with the administration of 5-50 mug/kg/min incremental doses in 3-minute intervals and up to 1 mg of atropine if needed to reach prespecified end points.

RESULTS

Regional left ventricular wall motion abnormality (WMA) at rest (fixed), with stress (inducible), or both were present in 54, 35, and 18 patients, respectively. In 38 patients who underwent coronary angiography, the sensitivity, specificity, and positive and negative predictive values of inducible WMA for predicting angiographic coronary artery disease (> or = 70% luminal diameter reduction) were 88%, 62%, 65%, and 87%, respectively. Cox regression analysis identified the presence of combined fixed and inducible WMA (ie, resting WMA that did not change during DSE, accompanied by new WMA evident during DSE; hazard ratio [HR] 5.6, P = .012), left atrial enlargement (HR 4.2, P = .002), and aortic valve sclerosis (HR 3.9, P = .013) as independent predictors of 48-month MACE (cardiac death, nonfatal acute myocardial infarction, and coronary revascularization after RT). Patients with all 3 predictors had a 48-month MACE of 60% compared with 5% in those with none (P = .007). Compared with those without WMA, patients with both fixed and inducible WMA had a higher rate of MACE at 48 months (7% vs 33%, P = .004).

CONCLUSION

In RT candidates, DSE can effectively identify those at low and high risk of MACE.

Cardiovascular risk assessment among potential kidney transplant candidates: approaches and controversies

Cardiovascular disease is the most common cause of death after kidney transplantation. However, uncertainties regarding the optimal assessment of cardiovascular risk in potential transplant candidates have produced controversy and inconsistency in pretransplantation cardiac evaluation practices. In this review, we consider the evidence supporting cardiac evaluation in kidney transplant candidates, generally focused on coronary artery disease, according to the World Health Organization principles for screening. The importance of pretransplant cardiac evaluation is supported by the high prevalence of coronary artery disease and the incidence and adverse consequences of acute coronary syndromes in this population. Testing for coronary artery disease may be performed noninvasively by using modalities that include nuclear myocardial perfusion studies and dobutamine stress echocardiography. These tests have prognostic value for mortality, but imperfect sensitivity and specificity for detecting angiographically defined coronary artery disease in patients with end-stage renal disease. Associations of angiographically-defined coronary artery disease with subsequent survival also are inconsistent, likely because plaque instability is more critical for infarction risk than angiographic stenosis. The efficacy and best methods of myocardial revascularization have not been examined in large contemporary clinical trials in patients with end-stage renal disease. Biomarkers, such as cardiac troponin, have prognostic value in end-stage renal disease, but require further study to determine clinical applications in directing more expensive and invasive cardiac evaluation.

Cardiovascular disease in patients with chronic kidney disease

Patients with chronic kidney disease have a high burden of cardiovascular morbidity and mortality. The vast majority of patients with chronic kidney disease do not progress to end stage renal failure, but do have a significantly higher incidence of all cardiovascular co-morbidities. Traditional cardiovascular risk factors only partially account for this increased incidence of cardiovascular disease. In patients with kidney disease the basic biology underlying cardiovascular disease may be similar to that in patients without kidney disease, but it would seem many more risk factors are involved as a consequence of renal dysfunction. Although emphasis is placed on delaying the progression of chronic kidney disease, it must be appreciated that for many patients it is vital to address their cardiovascular risk factors at an early stage to prevent premature cardiovascular death. This review examines available epidemiological evidence, discusses common cardiovascular risk factors in patients with chronic kidney disease, and suggests possible treatment strategies. Potential areas for important research are also described.

The diagnostic and prognostic value of tissue Doppler imaging during dobutamine stress echocardiography in end-stage renal disease

OBJECTIVE

To determine whether a quantitative measurement of peak systolic velocity (PSV) during dobutamine stress echocardiography (DSE) detects severe coronary artery disease (CAD) and predicts mortality in patients with end-stage renal disease.

METHODS

One hundred and forty renal transplant candidates had DSE and coronary angiography. DSE analysis was performed using conventional visual wall motion assessment, longitudinal PSV, and combining the two modalities. Failure of PSV to rise by more than 50% predicted an ischemic response. Significant CAD was defined as luminal stenosis greater than 70%.

RESULTS

The number of positive DSE studies according to conventional, PSV, and combined criteria was 41 (30%), 42 (31%), and 46 (34%) respectively. Forty patients (29%) had significant CAD at angiography. The sensitivity, specificity, positive and negative predictive values for conventional DSE analysis were 84, 91, 86, and 90% respectively. The same values for PSV analysis were 86, 92, 86, and 91%, respectively. The same values for the combination of visual and PSV analysis were 88, 94, 87, and 92% respectively. The differences between the three methods were not statistically significant. Sensitivity for single-vessel CAD (P=0.05) and circumflex artery disease (P=0.05) diagnosis was higher with PSV compared with conventional DSE analysis. Failure of PSV to rise by more than 50% during DSE was associated with significantly increased mortality (P=0.001).

CONCLUSION

A quantitative interpretation of DSE, based on the percentage rise of PSV during stress, accurately detects CAD and predicts prognosis in end-stage renal disease.

Prognostic risk stratification of myocardial ischaemia evaluated by gated myocardial perfusion SPECT in patients with chronic kidney disease

PURPOSE

The aim of this study was to identify useful predictors of cardiac events in patients with chronic kidney disease (CKD).

METHODS

Among 4,031 patients identified from the Japanese Assessment of Cardiac Events and Survival Study (J-ACCESS) database with suspected or known ischaemic heart disease, we selected 820 with an estimated glomerular filtration rate (eGFR) of < 60 ml/min per 1.73 m(2).

RESULTS

A total of 75 cardiac events developed among these 820 patients. The incidence of cardiac events was higher in the group with a lower eGFR. Multivariate Cox analysis indicated that age, diabetes mellitus, end-systolic volume, summed stress score (SSS) and eGFR were predictors of cardiac events. Event rates of patients with SSS >or= 9 were significantly higher in groups with lower eGFR values (< 40 and 40-49 ml/min).

CONCLUSION

The SSS value (>or= 9) is a reliable predictor of cardiac events and myocardial single photon emission computed tomography has incremental value for predicting cardiac events and survival in CKD.