Electrocardiographic abnormalities and uremic cardiomyopathy

Sudden cardiac death and chronic kidney disease: From pathophysiology to treatment strategies

Chronic kidney disease (CKD) patients demonstrate higher rates of cardiovascular mortality and morbidity; and increased incidence of sudden cardiac death (SCD) with declining kidney failure. Coronary artery disease (CAD) associated risk factors are the major determinants of SCD in the general population. However, current evidence suggests that in CKD patients, traditional cardiovascular risk factors may play a lesser role. Complex relationships between CKD-specific risk factors, structural heart disease, and ventricular arrhythmias (VA) contribute to the high risk of SCD. In dialysis patients, the occurrence of VA and SCD could be exacerbated by electrolyte shifts, divalent ion abnormalities, sympathetic overactivity, inflammation and iron toxicity. As outcomes in CKD patients after cardiac arrest are poor, primary and secondary prevention of SCD and cardiac arrest could reduce cardiovascular mortality in patients with CKD.

Drug safety of macrolide and quinolone antibiotics in a tertiary care hospital: administration of interacting co-medication and QT prolongation

PURPOSE

Some macrolide and quinolone antibiotics (MQABs) are associated with QT prolongation and life-threatening torsade de pointes (TdP) arrhythmia. MQAB may also inhibit cytochrome P450 isoenzymes and thereby cause pharmacokinetic drug interactions (DDIs). There is limited data on the frequency and management of such risks in clinical practice. We aimed to quantify co-administration of MQAB with interacting drugs and associated adverse drug reactions.

METHODS

We conducted an observational study within our pharmacoepidemiological database derived from electronic medical records of a tertiary care hospital. Among all users of MQAB associated with TdP, we determined the prevalence of additional QT-prolonging drugs and risk factors and identified contraindicated co-administrations of simvastatin, atorvastatin, or tizanidine. Electrocardiographic (ECG) monitoring and associated adverse events were validated in medical records.

RESULTS

Among 3444 administered courses of clarithromycin, erythromycin, azithromycin, ciprofloxacin, levofloxacin, or moxifloxacin, there were 1332 (38.7 %) with concomitant use of additional QT-prolonging drugs. Among those, we identified seven cases of drug-related QT prolongation, but 49.1 % had no ECG monitoring. Of all MQAB users, 547 (15.9 %) had hypokalemia. Forty-four MQAB users had contraindicated co-administrations of simvastatin, atorvastatin, or tizanidine and three of those related adverse drug reactions.

CONCLUSION

In the studied real-life setting, we found a considerable number of MQAB users with additional risk factors for TdP but no ECG monitoring. However, adverse drug reactions were rarely found, and costs vs. benefits of ECG monitoring have to be weighted. In contrast, avoidable risk factors and selected contraindicated pharmacokinetic interactions are clear targets for implementation as automated alerts in electronic prescribing systems.

Deficiency of Soluble α-Klotho as an Independent Cause of Uremic Cardiomyopathy

Cardiovascular disease (CVD) is the major cause of mortality for patients with chronic kidney disease (CKD). Cardiac hypertrophy, occurring in up to 95% patients with CKD (also known as uremic cardiomyopathy), increases their risk for cardiovascular death. Many CKD-specific risk factors of uremic cardiomyopathy have been recognized, such as secondary hyperparathyroidism, indoxyl sulfate (IS)/p-cresyl, and vitamin D deficiency. However, several randomized controlled trials have recently shown that these risk factors have little impact on the mortality of CVD. Klotho is a type 1 membrane protein predominantly produced in the kidney, and CKD is known to be a Klotho-deficient state. Because of its important role in FGF23 and phosphate metabolism, Klotho is believed to affect cardiac growth and function indirectly through FGF23 and phosphate. Recent studies showed that soluble Klotho protects the heart against stress-induced cardiac hypertrophy by inhibiting TRPC6 channel-mediated abnormal Ca(2+) signaling in the heart, and the decreased level of circulating soluble Klotho in CKD is an important cause of uremic cardiomyopathy independent of FGF23 and phosphate. These new evidence suggested that Klotho is an independent contributing factor for uremic cardiomyopathy and a possible new target for treatment of this disease.

Association of Dialysis Duration with Outcomes after Transplantation in a Japanese Cohort

BACKGROUND AND OBJECTIVES

Evidence regarding the differences in clinical outcomes after preemptive kidney transplantation (PKT) and non-PKT in Japan is lacking.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a retrospective cohort study at a single center in Japan. Consecutive patients ages >18 years old who had received a kidney transplant from a living donor between November of 2001 and December of 2013 at our institution (n=786) were enrolled. The primary study outcome was the occurrence of clinical events before the end of 2014. Clinical events were defined as any of the following: death with functioning graft (DWFG), graft loss, or post-transplant cardiovascular disease (CVD).

RESULTS

The median follow-up period was 61.0 (35.3-94.0) months. PKT was performed in 239 patients (30.4%). Clinical events occurred in 78 (9.9%). In the Cox proportional hazard model for univariate analysis, factors found to be associated with higher risk of clinical events included older age, men, ABO incompatibility, longer dialysis duration, diabetes, pretransplant CVD, and large ventricular mass index. PKT was associated with lower risk. Clinical event rate in patients who received a PKT was 3.3% compared with 10.8%, 11.1%, 10.4%, 10.2%, 16.7%, and 16.2% among patients who were on dialysis for <1, 1 to <2, 2 to <3, 3 to <4, 4 to <5, and ≥5 years before transplant, respectively (P=0.002). The multivariate analysis showed that ABO incompatibility (hazard ratio [HR], 2.98; 95% confidence interval [95% CI], 1.89 to 4.71), duration of dialysis per year (HR, 1.07; 95% CI, 1.03 to 1.11), and diabetes (HR, 3.54; 95% CI, 2.05 to 6.12) were only three independent risk factors for the incidence of clinical events.

CONCLUSIONS

Even in Japan, where the long-term outcomes of patients on hemodialysis are excellent, PKT could be beneficial to reduce DWFG, graft loss, and post-transplant CVD.

Estimated Glomerular Filtration Rate and Systolic Time Intervals in Risk Stratification for Increased Left Ventricular Mass Index and Left Ventricular Hypertrophy

Either decreased renal function or increased systolic time interval is associated with cardiac hypertrophy and poor cardiac outcome. The aim of this study was to evaluate combination of renal function and brachial systolic time intervals were associated with increased left ventricular mass index (LVMI) and left ventricular hypertrophy (LVH).In total of 990 patients were consecutively included in this study from January 2011 to December 2012. All study participants were further classified into 4 groups by the values of estimated glomerular filtration rate (eGFR) and ratio of brachial preejection period (bPEP) to brachial ejection time (bET). The classification of 4 groups were eGFR ≥ 45 mL/min/1.73 m and bPEP/bET < 0.38 (group 1), eGFR ≥ 45 ml/min/1.73 m and bPEP/bET ≥ 0.38 (group 2), eGFR < 45 mL/min/1.73 m and bPEP/bET < 0.38 (group 3), and eGFR < 45 mL/min/1.73 m and bPEP/bET ≥ 0.38 (group 4), respectively. Patients in groups 1 and 4 had the lowest and highest LVMI among 4 groups, respectively (P < 0.001). In multivariable analyses, increased LVMI and LVH were significantly associated with patients in groups 2, 3 and 4 (vs group 1) (P ≤ 0.019).Our study demonstrated that joined parameter of renal function and systolic time intervals, in terms of eGFR and bPEP/bET, might be an alternative method in risk stratification for increased LVMI and LVH.

[Prognostic value of biomarkers in chronic heart failure with preserved left ventricular ejection fraction]

The paper reviews major biomarkers for determining the prognosis in patients with chronic heart failure and preserved ejection fraction. It also considers cystatin C, one of the novel and probably the most practically important biomarkers.

Predictive Value of Echocardiographic Abnormalities and the Impact of Diastolic Dysfunction on In-hospital Major Cardiovascular Complications after Living Donor Kidney Transplantation

Patients with end-stage renal disease (ESRD) show characteristic abnormalities in cardiac structure and function. We evaluated the influence of these abnormalities on adverse cardiopulmonary outcomes after living donor kidney transplantation in patients with valid preoperative transthoracic echocardiographic evaluation. We then observed any development of major postoperative cardiovascular complications and pulmonary edema until hospital discharge. In-hospital major cardiovascular complications were defined as acute myocardial infarction, ventricular fibrillation/tachycardia, cardiogenic shock, newly-onset atrial fibrillation, clinical pulmonary edema requiring endotracheal intubation or dialysis. Among the 242 ESRD study patients, 9 patients (4%) developed major cardiovascular complications, and 39 patients (16%) developed pulmonary edema. Diabetes, ischemia-reperfusion time, left ventricular end-diastolic diameter (LVEDd), left ventricular mass index (LVMI), right ventricular systolic pressure (RVSP), left atrium volume index (LAVI), and high E/E' ratios were risk factors of major cardiovascular complications, while age, LVEDd, LVMI, LAVI, and high E/E' ratios were risk factors of pulmonary edema. The optimal E/E' cut-off value for predicting major cardiovascular complications was 13.0, showing 77.8% sensitivity and 78.5% specificity. Thus, the patient's E/E' ratio is useful for predicting in-hospital major cardiovascular complications after kidney transplantation. We recommend that goal-directed therapy employing E/E' ratio be enacted in kidney recipients with baseline diastolic dysfunction to avert postoperative morbidity. (http://Clinical Trials.gov number: NCT02322567).

The prognostic value of positive T-wave in lead aVR in hemodialysis patients

BACKGROUND

Given that cardiac disease is the leading cause of mortality in hemodialysis (HD) patients, identification of patients at risk for cardiac mortality is crucial. The aim of this study was to determine if positive T-wave amplitude in lead aVR (TaVR) was predictive of cardiovascular (CV) mortality and sudden cardiac death (SCD) in a group of HD patients.

METHODS AND RESULTS

After exclusion, 223 HD patients were prospectively followed-up for 25.43 ± 3.56 months. Patients were divided into TaVR negative (n = 186) and TaVR positive (n = 37) groups. Myocardial infarction, diabetes and beta-blocker therapy were more frequent in positive TaVR patients. Patients with upright TaVR were older, had higher left ventricular mass index, lower ejection fraction, higher calcium × phosphate product, higher troponin T level, higher prevalence of ST-T abnormalities, and increased width of QRS complex and QT interval, compared with patients with negative TaVR. A Kaplan-Meier analysis showed that the cumulative incidences of CV mortality as well as SCD were higher in patients with positive TaVR compared with those with negative TaVR (log-rank, p < 0.001 in both cases). A multivariate analysis selected age [hazard ratio (HR) 1.71, p < 0.001], heart rate (HR 1.42, p = 0.016), and positive TaVR (HR 2.21, p = 0.001) as well as age (HR 1.88, p < 0.001), and positive TaVR (HR 1.53, p = 0.014) as independent predictors of CV mortality and SCD, respectively.

CONCLUSION

In HD patients, positive TaVR is an independent and powerful predictor of CV mortality as well as SCD. This simple ECG parameter provides additional information beyond what is available with other known traditional risk factors and allows the identification of patients most at risk of CV events.

Effects of cinacalcet treatment on QT interval in hemodialysis patients

OBJECTIVE

Cinacalcet is a calcimimetic drug that acts via calcium-sensing receptors (CaSRs) and increases the sensitivity of CaSRs on the parathyroid gland; thus, it lowers calcium and phosphorus levels as well as parathormone levels. Prolongation of the QT interval is recognized as a risk factor for the development of ventricular arrhythmias and sudden death. Patients with end-stage renal disease (ESRD) are sensitive for QT prolongation and torsade de pointes more than the normal population. In this study, we aimed to evaluate the effects of cinacalcet on the electrocardiogram (ECG), particularly changes in the QT interval, in patients with ESRD.

METHODS

Thirty-seven patients (21 males and 16 females) undergoing maintenance hemodialysis for at least 12 months were included in this retrospective study. Patients receiving cardioactive and antiarrhythmic drugs and those having a history of any cardiac or cerebrovascular events, active malignancy, and infections were excluded. Baseline ECG measurements of patients were performed over the newest ECG measurements that were obtained within 1 month before initiating the cinacalcet treatment, and the ECG measurements of patients after the cinacalcet treatment were performed according to the most recent ECG that was taken within the last 1 week in the clinic. We recorded the heart rate and QT values of patients before and after treatment and then calculated the corrected QT values (QTc). The Statistical Package for the Social Sciences (SPSS) ver. 21.0 was used for statistical analysis.

RESULTS

The mean age of patients was 52.24±14.49 years. Prolongation of QTc was statistically significant compared with the baseline QTc value (baseline: 396.62±42.04 msec; after treatment: 404.97±43.47 msec; p=0.031). We found a positive correlation between the prolongation of QTc and treatment dose of cinacalcet (p<0.005, r=0.560).

CONCLUSION

Clinicians should be very careful for life threatening cardiac side effects while increasing the dose of cinacalcet treatment in hemodialysis patients who have a borderline or prolonged QTc interval.

Diosgenin, a steroidal saponin, prevents hypertension, cardiac remodeling and oxidative stress in adenine induced chronic renal failure rats

Prevention of hypertension, cardiac remodeling and oxidative stress in chronic renal failure (CRF) rats by diosgenin.

Cardiac, Inflammatory and Metabolic Parameters: Hemodialysis versus Peritoneal Dialysis

INTRODUCTION

Mortality in dialysis patients is higher than in the general population, and cardiovascular disease represents the leading cause of death. Hypertension and volume overload are important risk factors for the development of left ventricular hypertrophy (LVH) in hemodialysis (HD) and peritoneal dialysis (PD) patients. Other factors are mainly represented by hyperparathyroidism, vascular calcification, arterial stiffness and inflammation. The aim of this study was to compare blood pressure (BP) and metabolic parameters with cardiovascular changes [cardiothoracic ratio (CTR), aortic arch calcification (AAC) and LV mass index (LVMI)] between PD and HD patients.

MATERIALS AND METHODS

45 patients (23 HD and 22 PD patients) were enrolled. BP measurements, echocardiography and chest X-ray were performed in each patient to determine the LVMI and to evaluate the CTR and AAC. Inflammatory indexes, intact parathyroid hormone (iPTH) and arterial blood gas analysis were also evaluated.

RESULTS

LVMI was higher in PD than HD patients (139 ŷ 19 vs. 104 ŷ 22; p = 0.04). In PD patients, a significant correlation between iPTH, C-reactive protein and the presence of LVH was observed (r = 0.70, p = 0.04; r = 0.70, p = 0.03, respectively). The CTR was increased in PD patients as compared to HD patients, while no significant differences in cardiac calcifications were determined.

CONCLUSIONS

Our data indicate that HD patients present more effective BP control than PD patients. Adequate fluid and metabolic control are necessary to assess the adequacy of BP, which is strongly correlated with the increase in LVMI and with the increased CTR in dialysis patients. PD is a home therapy and allows a better quality of life, but PD patients may present a further increased cardiovascular risk if not adequately monitored.

Cardiovascular co-morbidity in chronic kidney disease: Current knowledge and future research needs

Chronic kidney disease (CKD) is recognised as a health concern globally and leads to high rates of morbidity, mortality and healthcare expenditure. CKD is itself an independent risk factor for unfavorable health outcomes that include cardiovascular disease (CVD). Coronary artery disease is the primary type of CVD in CKD patients and a significant cause of death among renal transplant patients. Traditional and non-traditional risk factors for CVD exist in patients with CKD. Traditional factors include smoking, hypertension, dyslipidemia and diabetes which are highly prevalent in CKD patients. Non-traditional risk factors of CKD are mainly uraemia-specific and increase in prevalence as kidney function declines. Some examples of uraemia-specific risk factors that have been well documented include low levels of haemoglobin, albuminuria, and abnormal bone and mineral metabolism. Therapeutic interventions targeted at more traditional risk factors which contribute to CVD, have not had the desired effect on lowering CVD events and mortality in those suffering with CKD. Future research is warranted to delineate clear evidence to the benefit of modifying non-traditional risk factors.

Long-Term Impact of Different Immunosuppressive Drugs on QT and PR Intervals in Renal Transplant Patients

BACKGROUND

Sudden cardiac deaths due to arrhythmias are thought to be an important cause of mortality in patients with renal transplants. Exposure to immunosuppressive drugs may lead to QT or PR interval abnormalities which may consequently cause arrhythmias. Our study investigated the long term impact of four different immunosuppressive drugs on PR and corrected QT intervals (QTc) in renal transplant patients

METHODS

The study population consisted of 98 kidney transplant recipients. Study patients were receiving immunosuppressive management with tacrolimus, cyclosporine A, everolimus or azathioprine according to the local protocols. QTc and PR intervals obtained from the most recent post-transplant electrocardiograms were compared with the pre-transplant intervals dated before the transplantation procedure.

RESULTS

Post-transplant QTc intervals had prolonged significantly in comparison to the pre-transplant QTc intervals in all groups. However, there were no significant differences between the immunosuppressive agents with regard to post-transplant QTc interval prolongation (p > 0.05). There were no significant differences between the groups with regard to the pre and post-transplant PR interval changes (p > 0.05).

CONCLUSIONS

QT interval prolongation, a marker of risk for arrhythmias and sudden death, is highly prevalent among kidney transplant patients receiving different classes of immunosuppressive drugs.

Cardiovascular morbidity and mortality after kidney transplantation

Kidney transplantation is the optimal treatment for patients with end stage renal disease (ESRD) who would otherwise require dialysis. Patients with ESRD are at dramatically increased cardiovascular (CV) risk compared with the general population. As well as improving quality of life, successful transplantation accords major benefits by reducing CV risk in these patients. Worldwide, cardiovascular disease remains the leading cause of death with a functioning graft and therefore is a leading cause of graft failure. This review focuses on the mechanisms underpinning excess CV morbidity and mortality and current evidence for improving CV risk in kidney transplant recipients. Conventional CV risk factors such as hypertension, diabetes mellitus, dyslipidaemia and pre-existing ischaemic heart disease are all highly prevalent in this group. In addition, kidney transplant recipients exhibit a number of risk factors associated with pre-existing renal disease. Furthermore, complications specific to transplantation may ensue including reduced graft function, side effects of immunosuppression and post-transplantation diabetes mellitus. Strategies to improve CV outcomes post-transplantation may include pharmacological intervention including lipid-lowering or antihypertensive therapy, optimization of graft function, lifestyle intervention and personalizing immunosuppression to the individual patients risk profile.

Association of Corrected QT and QT Dispersion with Echocardiographic and Laboratory Findings in Uremic Patients under Chronic Hemodialysis

Introduction:

Cardiovascular disease is the most common cause of mortality in dialysis patients. Chronic renal failure and hemodialysis (HD) patients may have longer corrected QT (QTc) interval compared with the normal population. Long QTc interval may be a predictor of ventricular arrhythmia and cardiovascular mortality in these patients and hence the aim of this study was the evaluation of the relationship between QTc interval and some echocardiographic findings and laboratory exam results in HD patients.

Materials and Methods:

In a cross-sectional study, 60 HD patients with age >18 years and the dialysis duration >3 months were enrolled. Blood samples were taken, and electrocardiography and echocardiography were done before the dialysis session in the patients.

Results:

Mean age of the patients was 56.15 ± 14.6 years. QTc interval of the patients was 0.441 ± 0.056 s and QT dispersion (QTd) was 64.17 ± 25.93 ms. There was no statistically significant relationship between QTc interval and QTd with duration of dialysis, body mass index, age, and gender (P > 0.05). There was also no significant relationship between QTc interval and QTd with mitral regurgitation, tricuspid regurgitation and aortic insufficiency (P > 0.05). In addition, QTc interval and QTd of the patients had not any correlation with serum parathormon and serum Ca, K, HCO₃ (P > 0.05).

Conclusion:

Based on our results, in HD patients, QTc interval and QTd were not correlated with echocardiographic findings or laboratory exam results. Therefore, it can be concluded that QTc interval prolongation probably has not any correlation with cardiac mortality of the HD patients.

Long-term effects of spironolactone in peritoneal dialysis patients

ESRD treated with dialysis is associated with increased left ventricular hypertrophy, which, in turn, is related to high mortality. Mineralocorticoid receptor antagonists improve survival in patients with chronic heart failure; however, the effects in patients undergoing dialysis remain uncertain. We conducted a multicenter, open-label, prospective, randomized trial with 158 patients receiving angiotensin-converting enzyme inhibitor or angiotensin type 1 receptor antagonist and undergoing peritoneal dialysis with and without (control group) spironolactone for 2 years. As a primary endpoint, rate of change in left ventricular mass index assessed by echocardiography improved significantly at 6 (P=0.03), 18 (P=0.004), and 24 (P=0.01) months in patients taking spironolactone compared with the control group. Rate of change in left ventricular ejection fraction improved significantly at 24 weeks with spironolactone compared with nontreatment (P=0.02). The benefits of spironolactone were clear in patients with reduced residual renal function. As secondary endpoints, renal Kt/V and dialysate-to-plasma creatinine ratio did not differ significantly between groups during the observation period. No serious adverse effects, such as hyperkalemia, occurred. In this trial, spironolactone prevented cardiac hypertrophy and decreases in left ventricular ejection fraction in patients undergoing peritoneal dialysis, without significant adverse effects. Further studies, including those to determine relative effectiveness in women and men and to evaluate additional secondary endpoints, should confirm these data in a larger cohort.

Risk of sudden cardiac death in chronic kidney disease

The review discusses the epidemiology and the possible underlying mechanisms of sudden cardiac death (SCD) in chronic kidney disease (CKD), and highlights the unmet clinical need for noninvasive risk stratification strategies in these patients. Although renal dysfunction shares common risk factors and often coexists with atherosclerotic cardiovascular disease, the presence of renal impairment increases the risk of arrhythmic complications to an extent that cannot be explained by the severity of the atherosclerotic process. Renal impairment is an independent risk factor for SCD from the early stages of CKD; the risk increases as renal function declines and reaches very high levels in patients with end-stage renal disease on dialysis. Autonomic imbalance, uremic cardiomyopathy, and electrolyte disturbances likely play a role in increasing the arrhythmic risk and can be potential targets for treatment. Cardioverter defibrillator treatment could be offered as lifesaving treatment in selected patients, although selection strategies for this treatment mode are presently problematic in dialyzed patients. The review also examines the current experience with risk stratification tools in renal patients and suggests that noninvasive electrophysiological testing during dialysis may be of clinical value as it provides the necessary standardized environment for reproducible measurements for risk stratification purposes.

Diastolic dysfunction is associated with an increased risk of contrast-induced nephropathy: a retrospective cohort study

Background

Contrast-induced nephropathy (CIN) is the third leading cause of hospital-acquired acute kidney injury, and it is associated with poor long-term clinical outcomes. Although systolic heart failure is a well-known risk factor for CIN, no studies have yet evaluated the association between diastolic dysfunction and CIN.

Methods

We conducted a retrospective study of 735 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) and had an echocardiography performed within one month of the procedure at our institute, between January 2009 and December 2010. CIN was defined as an increase of ≥ 0.5 mg/dL or ≥ 25% in serum creatinine level during the 72 hours following PTCA.

Results

CIN occurred in 64 patients (8.7%). Patients with CIN were older, had more comorbidities, and had an intra-aortic balloon pump (IABP) placed more frequently during PTCA than patients without CIN. They showed greater high-sensitivity C-reactive protein (hs-CRP) levels and lower estimated glomerular filtration rates (eGFR). Echocardiographic findings revealed lower ejection fraction and higher left atrial volume index and E/E’ in the CIN group compared with non-CIN group. When patients were classified into 3 groups according to the E/E’ values of 8 and 15, CIN occurred in 42 (21.6%) patients in the highest tertile compared with 20 (4.0%) in the middle and 2 (4.3%) in the lowest tertile (p < 0.001). In multivariate logistic regression analysis, E/E’ > 15 was identified as an independent risk factor for the development of CIN after adjustment for age, diabetes, dose of contrast media, IABP use, eGFR, hs-CRP, and echocardiographic parameters [odds ratio (OR) 2.579, 95% confidence interval (CI) 1.082-5.964, p = 0.035]. In addition, the area under the receiver operating characteristic curve of E/E’ was 0.751 (95% CI 0.684-0.819, p < 0.001), which was comparable to that of ejection fraction and left atrial volume index (0.739 and 0.656, respectively, p < 0.001).

Conclusions

This study demonstrated that, among echocardiographic variables, E/E' was an independent predictor of CIN. This in turn suggests that diastolic dysfunction may be a useful parameter in CIN risk stratification.

Relationship of left ventricular hypertrophy and diastolic function with cardiovascular and renal outcomes in African Americans with hypertensive chronic kidney disease

African Americans with hypertension are at high risk for adverse outcomes from cardiovascular and renal disease. Patients with stage 3 or greater chronic kidney disease have a high prevalence of left ventricular (LV) hypertrophy and diastolic dysfunction. Our goal was to study prospectively the relationships of LV mass and diastolic function with subsequent cardiovascular and renal outcomes in the African American Study of Kidney Disease and Hypertension cohort study. Of 691 patients enrolled in the cohort, 578 had interpretable echocardiograms and complete relevant clinical data. Exposures were LV hypertrophy and diastolic parameters. Outcomes were cardiovascular events requiring hospitalization or causing death; a renal composite outcome of doubling of serum creatinine or end-stage renal disease (censoring death); and heart failure. We found strong independent relationships between LV hypertrophy and subsequent cardiovascular (hazard ratio, 1.16; 95% confidence interval, 1.05-1.27) events, but not renal outcomes. After adjustment for LV mass and clinical variables, lower systolic tissue Doppler velocities and diastolic parameters reflecting a less compliant LV (shorter deceleration time and abnormal E/A ratio) were significantly (P<0.05) associated with future heart failure events. This is the first study to show a strong relationship among LV hypertrophy, diastolic parameters, and adverse cardiac outcomes in African Americans with hypertension and chronic kidney disease. These echocardiographic risk factors may help identify high-risk patients with chronic kidney disease for aggressive therapeutic intervention.

Ratio of transmitral E-wave velocity to early diastole mitral annulus velocity with cardiovascular and renal outcomes in chronic kidney disease

BACKGROUND/AIMS

Impaired left ventricular diastolic function and increased left ventricular filling pressure are frequently noted in patients with chronic kidney disease (CKD), even in early stages. The association of increased left ventricular filling pressure with cardiovascular and renal outcomes remains uncertain in CKD. This study is designed to assess whether the ratio of transmitral E-wave velocity (E) to early diastole mitral velocity (Ea) is associated with cardiovascular events and progression to dialysis in patients with CKD stages 3-5.

METHODS

This longitudinal study enrolled 356 predialysis CKD patients. Cardiovascular events were defined as cardiovascular death, hospitalization for unstable angina, nonfatal myocardial infarction, ventricular tachycardia, hospitalization for congestive heart failure, transient ischemia attack, and stroke. The renal endpoint was defined as commencement of dialysis. The relative cardiovascular events and renal endpoints risks were analyzed by Cox regression methods.

RESULTS

The high E/Ea was independently associated with old age, cerebrovascular disease, congestive heart failure, high systolic blood pressure, hypertriglyceridemia, low hemoglobin, proteinuria, and worse echocardiographic profiles. Besides, the high E/Ea increased the risk of cardiovascular events (hazard ratio (HR) 1.067; 95% confidence interval (CI) 1.017-1.119; p = 0.008) and progression to dialysis (HR 1.042; 95% CI 1.000-1.085; p = 0.048).

CONCLUSIONS

Our study in patients of CKD stages 3-5 demonstrated the high E/Ea was associated with increased cardiovascular events and progression to dialysis. Assessment of the E/Ea by Doppler echocardiography is useful for predicting the risk of adverse cardiovascular and renal outcomes in CKD patients.

High-output heart failure: how to define it, when to treat it, and how to treat it

Although hemodialysis patients who initiate and maintain a permanent form of dialysis vascular access have improved all-cause and cardiovascular survival compared with those who use catheters, the presence of an arteriovenous fistula has been shown to have a short-term, adverse effect on cardiac function. Through its effect as a left-to-right extracardiac shunt, the arteriovenous fistula can increase cardiac workload substantially, and, in certain patients, result in a high-output state and resultant heart failure over time. Here we review the mechanisms by which dialysis arteriovenous access may promote the development of high-output cardiac failure in end-stage renal disease patients, describe risk factors for and the diagnosis of high-output heart failure, and suggest management strategies for patients who develop high-output heart failure.

Framingham risk score with cardiovascular events in chronic kidney disease

The Framingham Risk Score (FRS) was developed to predict coronary heart disease in various populations, and it tended to under-estimate the risk in chronic kidney disease (CKD) patients. Our objectives were to determine whether FRS was associated with cardiovascular events, and to evaluate the role of new risk markers and echocardiographic parameters when they were added to a FRS model. This study enrolled 439 CKD patients. The FRS is used to identify individuals categorically as “low” (<10% of 10-year risk), “intermediate” (10–20% risk) or “high” risk (≧ 20% risk). A significant improvement in model prediction was based on the −2 log likelihood ratio statistic and c-statistic. “High” risk (v.s. “low” risk) predicts cardiovascular events either without (hazard ratios [HR] 2.090, 95% confidence interval [CI] 1.144 to 3.818) or with adjustment for clinical, biochemical and echocardiographic parameters (HR 1.924, 95% CI 1.008 to 3.673). Besides, the addition of albumin, hemoglobin, estimated glomerular filtration rate, proteinuria, left atrial diameter >4.7 cm, left ventricular hypertrophy or left ventricular ejection fraction<50% to the FRS model significantly improves the predictive values for cardiovascular events. In CKD patients, “high” risk categorized by FRS predicts cardiovascular events. Novel biomarkers and echocardiographic parameters provide additional predictive values for cardiovascular events. Future study is needed to assess whether risk assessment enhanced by using these biomarkers and echocardiographic parameters might contribute to more effective prediction and better care for patients.

Left atrial diameter and albumin with renal outcomes in chronic kidney disease

BACKGROUND AND AIM

Echocardiographic left atrial diameter (LAD) has been documented to be an independent predictor of adverse cardiovascular outcomes in various populations. An enlarged left atrium is frequently noted in chronic kidney disease (CKD). We examined the association between albumin and indexed LAD (indexed to height) and assessed whether the combination of indexed LAD and albumin was independently associated with renal outcomes in patients with CKD stages 3-5.

METHODS

This longitudinal study enrolled 395 patients, who were classified into four groups according to median values of indexed LAD (LAD/height) and albumin. The change in renal function was measured by estimated glomerular filtration rate (eGFR) slope. Rapid renal progression was defined as eGFR slope less than -3 ml/min/1.73 m(2)/year. The renal end point was defined as commencement of dialysis.

RESULTS

Albumin was significantly associated with indexed LAD (β = -0.108, P = 0.024). During follow-up period, seventy-four patients started dialysis. After the multivariate analysis, the group with higher indexed LAD and lower albumin was independently associated with rapid renal progression (odds ratio, 7.979; 95% confidence interval [CI], 3.028 to 21.025) and progression to dialysis (hazard ratio, 2.352; 95% CI, 1.078 to 5.131).

CONCLUSIONS

Our findings show that albumin is independently associated with indexed LAD and suggest that the combination of increased indexed LAD and hypoalbuminemia is independently associated with rapid renal progression and progression to dialysis in patients with CKD. Assessments of serum albumin and indexed LAD by echocardiography are useful for predicting the risk for adverse renal outcomes.

Association of uric acid and left ventricular mass index with renal outcomes in chronic kidney disease

BACKGROUND

Hyperuricemia and left ventricular (LV) hypertrophy are prevalent in chronic kidney disease (CKD), but the association of uric acid (UA) and left ventricular mass index (LVMI) with renal outcomes in patients with CKD is unclear. We conducted a study to assess whether the combination of UA and LVMI is associated with renal outcomes in patients with CKD of stages 3-5.

METHODS

This longitudinal study enrolled 540 patients, who were classified into four groups according to sex-specific median values of UA and LVMI. The study investigated the associations of the study groups with progression to dialysis, rapid progression of decline in renal function (decline in estimated glomerular filtration rate (eGFR) > 3ml/min/1.73 m(2)/year), and change in eGFR, using Cox proportional hazards modeling, logistic regression analysis, and linear mixed-effects modeling, respectively.

RESULTS

The follow-up period for the study was 33.4 (19.8-39.6) months. The average number of serum creatinine measurements during the follow-up period was 8 (range, 5-12). Multivariate analyses demonstrated an association of the group with a higher UA and LVMI with an increased rate of progression to dialysis (hazard ratio (HR), 1.830; 95% confidence interval (CI), 1.007 to 3.326; P = 0.048) and with rapid progression of decline in renal function (odds ratio (OR), 2.231; 95% CI, 1.058-4.705; P = 0.04). Additionally, the linear mixed-effects model showed that the decrease in eGFR over time was more rapid in the group with a higher UA and LVMI than in the other groups (P < 0.04).

CONCLUSIONS

Our findings show that the combination of a higher UA and LVMI is a risk factor for progression to dialysis and rapid progression of decline in renal function in patients with CKD of stages 3-5.

Cardiovascular disease in chronic kidney disease: untying the Gordian knot

Chronic kidney disease (CKD) affects around 10-13% of the general population, with only a small proportion in end stage renal disease (ESRD), either on dialysis or awaiting renal transplantation. It is well documented that CKD patients have an extremely high risk of developing cardiovascular disease (CVD) compared with the general population, so much so that in the early stages of CKD patients are more likely to develop CVD than they are to progress to ESRD. Various pathophysiological pathways and explanations have been advanced and suggested to account for this, including endothelial dysfunction, dyslipidaemia, inflammation, left ventricular hypertrophy and cardiac autonomic dysfunction. In this review, we try to understand and further explore the link between CKD and CVD, as well as offering interventional advice where available, while exposing the current lack of RCT-based research and trial evidence in this area. We also suggest pragmatic Interim measures we could take while we wait for definitive RCTs.

Prevention of sudden cardiac death in patients with chronic kidney disease

Cardiovascular deaths account for about 40% of all deaths of patients with chronic kidney disease (CKD), particularly those on dialysis, while sudden cardiac death (SCD) might be responsible for as many as 60% of SCD in patients undergoing dialysis. Studies have demonstrated a number of factors occurring in hemodialysis (HD) that could lead to cardiac arrhythmias. Patients with CKD undergoing HD are at high risk of ventricular arrhythmia and SCD since changes associated with renal failure and hemodialysis-related disorders overlap. Antiarrhythmic therapy is much more difficult in patients with CKD, but the general principles are similar to those in patients with normal renal function - at first, the cause of arrhythmias should be found and eliminated. Also the choice of therapy is narrowed due to the altered pharmacokinetics of many drugs resulting from renal failure, neurotoxicity of certain drugs and their complex interactions. Cardiac pacing in elderly patients is a common method of treatment. Assessment of patients’ prognosis is important when deciding whether to implant complex devices. There are reports concerning greater risk of surgical complications, which depends also on the extent of the surgical site. The decision concerning implantation of a pacing system in patients with CKD should be made on the basis of individual assessment of the patient.

Effect of early initiation of dialysis on cardiac structure and function: results from the echo substudy of the IDEAL trial

BACKGROUND

Abnormalities of cardiac structure and function are common in patients undergoing dialysis, and cardiovascular disease is the major cause of mortality in this group. Heart failure is a common clinical manifestation of cardiovascular disease and is preceded by left ventricular hypertrophy (LVH). There are variable reports about the impact of dialysis on LVH, both deleterious and beneficial. Our study investigated whether the timing of the initiation of dialysis therapy had an impact on cardiac structure and function.

STUDY DESIGN

Randomized controlled trial.

SETTING & PARTICIPANTS

This is a cardiac substudy involving 182 patients with stage 5 chronic kidney disease in the IDEAL (Initiating Dialysis Early and Late) trial.

INTERVENTION

The IDEAL trial randomly assigned patients on the basis of estimated glomerular filtration rate (eGFR), calculated using the Cockcroft-Gault equation, to start dialysis therapy early (GFR, 10-14 mL/min/1.73 m(2)), with the others starting late (GFR, 5-7 mL/min/1.73 m(2)).

OUTCOMES & MEASUREMENTS

Echocardiograms were obtained at baseline and 12 months after randomization. Primary outcomes were change in left ventricular mass indexed for height (LVMi) between baseline and 12 months, left ventricular ejection fraction, left ventricular systolic annular velocity, ratio of mitral inflow velocity (E) to mitral annular velocity (Ea) (E/Ea), and left atrial volume indexed for height (LAVi).

RESULTS

LVMi at baseline was elevated, but similar in both groups, with no significant change within or between groups at 12 months. E/Ea and LAVi were increased at baseline, consistent with significant diastolic dysfunction; there were no differences between groups at 12 months and no changes were observed for left ventricular volumes, left ventricular ejection fraction, stroke volume, and other echocardiographic parameters.

LIMITATIONS

Small multicenter study using echocardiography.

CONCLUSIONS

Advanced cardiac disease in these patients with stage 5 chronic kidney disease did not progress during the 12-month study period and planned early initiation of dialysis therapy did not result in differences in any echocardiographic variables of cardiac structure and function.

Race and gender variation in the QT interval and its association with mortality in patients with coronary artery disease: results from the Duke Databank for Cardiovascular Disease (DDCD)

BACKGROUND

In several studies, prolongation of the corrected QT (QTc) interval has been associated with an increased risk of cardiac events. However, data on race and gender variation in the QTc and its associated risk of death are lacking.

METHODS

We prospectively followed 19,252 subjects who underwent cardiac catheterization and had at least 1 native coronary artery stenosis ≥75%. Automated QTc measurements were obtained from a baseline electrocardiogram.

RESULTS

The mean age of the population was 62.4 years, with 35% being female and 20% being black. The QTc varied by gender and race (417.9 ± 34.4 ms in men and 433.4 ± 33.6 ms in women, 422.1 ± 34.3 ms in whites and 428.1 ± 36.9 ms in blacks; P < .0001 for both). Risk factors most strongly associated with a prolonged QTc were lower ejection fraction, higher diastolic blood pressure, history of myocardial infarction, and lower glomerular filtration rate. Black race and female gender were also independently associated with a prolonged QTc, after adjustment for cardiac risk factors. Moreover, there was an independent association between QTc and all-cause mortality (hazard ratio 1.037 per 10-ms increase, P < .0001). The increased mortality risk associated with a 10-ms increase in the QTc interval was significantly greater for men compared with women (4.6% vs 2.4%, P = .004) and slightly greater for blacks compared with other races (5.0% vs 3.3%, P = .057).

CONCLUSIONS

Among patients with coronary artery disease, QTc prolongation is independently associated with all-cause mortality. The increased mortality risk is higher for men than for women, with a trend toward higher mortality in blacks.

Significant correlation between left ventricular systolic and diastolic dysfunction and decreased glomerular filtration rate

Cardiac dysfunction portends a poor prognosis in renal failure and vice versa. Functional abnormalities of heart in patients with renal insufficiency were frequently noted. The aim of this study is to assess the relationship between left ventricular systolic and diastolic function and renal function in patients with various degrees of renal function. This cross-sectional study included 167 patients from our Outpatient Department of Internal Medicine. Left ventricular systolic and diastolic functions were assessed by echocardiography. Clinical and echocardiographic parameters were compared and analyzed. The prevalence of left ventricular ejection fraction (LVEF) <50% was 31.7% and the average value of the ratio of peak early transmitral filling wave velocity (E) to early diastolic velocity of lateral mitral annulus (Ea) was 11.4 ± 6.2. After the multivariate analysis, low systolic blood pressure, rapid heart rate, low albumin, and low estimated glomerular filtration rate (eGFR) (odds ratio = 0.957; 95% confidence interval = 0.929-0.986; p = 0.004) levels were associated with LVEF < 50%. Besides, old age, low albumin, low eGFR (β = -0.172; p = 0.043), and high uric acid levels were associated with high E/Ea. Our findings show a significant correlation between LVEF < 50% and high E/Ea and decreased eGFR.

Regression of left ventricular mass following conversion from conventional hemodialysis to thrice weekly in-centre nocturnal hemodialysis

Background

Increased left ventricular mass (LVM) is associated with adverse outcomes in patients receiving chronic hemodialysis. Among patients receiving conventional hemodialysis (CHD, 3×/week, 4 hrs/session), we evaluated whether dialysis intensification with in-centre nocturnal hemodialysis (INHD, 3×/week, 7-8 hrs/session in the dialysis unit) was associated with regression of LVM.

Methods

We conducted a retrospective cohort study of CHD recipients who converted to INHD and received INHD for at least 6 months. LVM on the first echocardiogram performed at least 6 months post-conversion was compared to LVM pre-conversion. In a secondary analysis, we examined echocardiograms performed at least 12 months after starting INHD. The effect of conversion to INHD on LVM over time was also evaluated using a longitudinal analysis that incorporated all LVM data on patients with 2 or more echocardiograms.

Results

Thirty-seven patients were eligible for the primary analysis. Mean age at conversion was 49 ± 12 yrs and 30% were women. Mean pre-conversion LVM was 219 ± 66 g and following conversion, LVM declined by 32 ± 58 g (p = 0.002). Among patients whose follow-up echocardiogram occurred at least 12 months following conversion, LVM declined by 40 ± 56 g (p = 0.0004). The rate of change of LVM decreased significantly from 0.4 g/yr before conversion, to -11.7 g/yr following conversion to INHD (p < 0.0001).

Conclusion

Conversion to INHD is associated with a significant regression in LVM, which may portend a more favourable cardiovascular outcome. Our preliminary findings support the need for randomized controlled trials to definitively evaluate the cardiovascular effects of INHD.

Impact of vascular calcification on corrected QT interval at the time of renal transplantation

BACKGROUND/AIMS

Sudden death is the major cause of cardiac mortality in dialysis patients, accounting for approximately 60% of cardiovascular deaths. A prolonged QT interval and arterial calcification have been associated with increased cardiovascular morbidity and mortality in different patient populations including patients with chronic kidney disease (CKD). In the present study, we aimed to elucidate the association of vascular calcification with corrected QT interval duration in patients with end-stage renal disease.

METHODS

We performed a single-center cross-sectional study in patients referred for renal transplantation. Patients taking QT-prolonging agents or with conduction abnormalities were excluded. Aortic calcifications were scored by means of lumbar X-rays.

RESULTS

In the final analysis, 193 patients (118 men, 52 years old) were included. A prolonged QT interval was observed in 26% of the patients. Multivariate analysis showed an independent and direct association between corrected QT duration and the extent of aortic calcifications (p = 0.0004) independent of age, gender, cardiovascular history, electrolytes and parameters of mineral metabolism.

CONCLUSIONS

A prolonged QT interval is prevalent in patients with CKD stage 5D. Aortic calcification is associated with a prolonged QT duration, independent of traditional determinants.

Visual three-dimensional representation of beat-to-beat electrocardiogram traces during hemodiafiltration

This study evaluated the usefulness of the three-dimensional representation of electrocardiogram traces (3DECG) to reveal acute and gradual changes during a full session of hemodiafiltration (HDF) in end-stage renal disease (ESRD) patients. Fifteen ESRD patients were included (six men, nine women, age 46 ± 19 years old). Serum electrolytes, blood pressure, heart rate, and blood urea nitrogen (BUN) were measured before and after HDF. Continuous electrocardiograms (ECGs) obtained by Holter monitoring during HDF were used to produce the 3DECG. Several major disturbances were identified by 3DECG images: increase in QRS amplitude (47%), decrease in T-wave amplitude (33%), increase in heart rate (33%), and occurrence of arrhythmia (53%). Different arrhythmia types were often concurrent and included isolated supraventricular premature beats (N = 5), atrial fibrillation or atrial bigeminy (N = 2), and isolated premature ventricular beats (N = 6). Patients with decrease in T-wave amplitude had higher potassium and BUN (both before HDF and total removal) than those without decrease in T-wave amplitude (P < 0.05). Concurrent acute and gradual ECG changes during HDF are identified by the 3DECG, which could be useful as a preventive and prognostic method.

Echocardiographic parameters are independently associated with rate of renal function decline and progression to dialysis in patients with chronic kidney disease

BACKGROUND AND OBJECTIVES

Cardiac abnormalities were frequently noted in patients with chronic kidney disease (CKD). This study is designed to assess whether echocardiographic parameters are associated with rate of renal function decline and progression to dialysis in CKD stage 3 to 5 patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This longitudinal study enrolled 415 patients. The renal end point was defined as commencement of dialysis. The change in renal function was measured by estimated GFR (eGFR) slope.

RESULTS

Progression to dialysis was predicted by wide pulse pressure, low albumin, low hemoglobin, high calcium-phosphorous product, proteinuria, diuretics use, and concentric left ventricular hypertrophy (LVH) (hazard ratio, 2.03; 95% confidence interval [CI], 1.00 to 4.10; P = 0.05). The eGFR slope was negatively associated with total cholesterol, uric acid, proteinuria, diuretics use, and left atrial (LA) diameter (change in slope, -0.50; 95% CI, -0.89 to -0.11; P = 0.01) and positively associated with albumin and left ventricular ejection fraction (LVEF) (change in slope, 0.06; 95% CI, 0.03 to 0.08; P < 0.001).

CONCLUSIONS

Our study in patients of CKD stage 3 to 5 demonstrated that concentric LVH was associated with progression to dialysis, and that increased LA diameter and decreased LVEF were associated with faster renal function decline. Echocardiography may help identify high-risk groups with progressive decline in renal function to dialysis and rapid progression of renal dysfunction in CKD stage 3 to 5 patients.

Association of rs10918594 polymorphisms of nitric oxide synthase 1 adaptor protein (NOS1AP) with QTc interval prolongation during kidney transplantation

BACKGROUND

The mechanisms of sudden cardiac death are difficult to recognize, but repolarization disturbances have been shown to be the cause. The purpose of this study was to investigate whether the polymorphism of nitric oxide synthase 1 adaptor protein (NOS1AP) was related to the risk of occurrence of corrected QTc-interval prolongation and ventricular arrhythmias recorded on electrocardiography (ECG) Holter monitoring in kidney transplant recipients.

STUDY DESIGN

The 75 adult first kidney transplant patients included 43 men with an overall mean age of 45±12 years (range, 20-68). Additional patient monitoring during the procedure and in the postoperative period consisted of a continuous ECG tracing recording and investigation of the rs10918594 NOS1AP polymorphism.

RESULTS

We observed Transient QTc-interval prolongation during the perioperative period. NOS1AP genotypes were in Hardy-Weinberg equilibrium. For further statistical analysis, we combined GG homozygotes and CG heterozygotes because of the small numbers available; therefore, only a dominant mode of inheritance was investigated. There were no gender differences in QTc-interval patterns. Analysis of variance with repeated measures revealed no interaction between NOS1AP and QTc-interval values taken at various times among the kidney recipients.

CONCLUSIONS

The transplantation procedure may lead to dynamic repolarization disturbances, which may produce an increased risk of severe arrhythmias despite optimization of patient status. The NOS1AP rs203462 polymorphisms did not correlate with an increased risk of QT interval prolongation among kidney recipients.

The use of group sequential, information-based sample size re-estimation in the design of the PRIMO study of chronic kidney disease

BACKGROUND

Chronic kidney disease is associated with a marked increase in risk for left ventricular hypertrophy and cardiovascular mortality compared with the general population. Therapy with vitamin D receptor activators has been linked with reduced mortality in chronic kidney disease and an improvement in left ventricular hypertrophy in animal studies.

PURPOSE

PRIMO (Paricalcitol capsules benefits in Renal failure Induced cardia MOrbidity) is a multinational, multicenter randomized controlled trial to assess the effects of paricalcitol (a selective vitamin D receptor activator) on mild to moderate left ventricular hypertrophy in patients with chronic kidney disease.

METHODS

Subjects with mild-moderate chronic kidney disease are randomized to paricalcitol or placebo after confirming left ventricular hypertrophy using a cardiac echocardiogram. Cardiac magnetic resonance imaging is then used to assess left ventricular mass index at baseline, 24 and 48 weeks, which is the primary efficacy endpoint of the study. Because of limited prior data to estimate sample size, a maximum information group sequential design with sample size re-estimation is implemented to allow sample size adjustment based on the nuisance parameter estimated using the interim data. An interim efficacy analysis is planned at a pre-specified time point conditioned on the status of enrollment. The decision to increase sample size depends on the observed treatment effect. A repeated measures analysis model, using available data at Week 24 and 48 with a backup model of an ANCOVA analyzing change from baseline to the final nonmissing observation, are pre-specified to evaluate the treatment effect. Gamma-family of spending function is employed to control family-wise Type I error rate as stopping for success is planned in the interim efficacy analysis.

LIMITATIONS

If enrollment is slower than anticipated, the smaller sample size used in the interim efficacy analysis and the greater percent of missing week 48 data might decrease the parameter estimation accuracy, either for the nuisance parameter or for the treatment effect, which might in turn affect the interim decision-making.

CONCLUSIONS

The application of combining a group sequential design with a sample-size re-estimation in clinical trial design has the potential to improve efficiency and to increase the probability of trial success while ensuring integrity of the study.

Stepwise increases in left ventricular mass index and decreases in left ventricular ejection fraction correspond with the stages of chronic kidney disease in diabetes patients

AIMS

Patients with diabetic nephropathy are reported to have a high prevalence of left ventricular structural and functional abnormalities. This study was designed to assess the determinants of left ventricular mass index (LVMI) and left ventricular ejection fraction (LVEF) in diabetic patients at various stages of chronic kidney disease (CKD).

METHODS

This cross-sectional study enrolled 285 diabetic patients with CKD stages 3 to 5 from our outpatient department of internal medicine. Clinical and echocardiographic parameters were compared and analyzed.

RESULTS

We found a significant stepwise increase in LVMI (P < 0.001), LVH (P < 0.001), and LVEF <55% (P = 0.013) and a stepwise decrease in LVEF (P = 0.038) corresponding to advance in CKD stages.

CONCLUSIONS

Our findings suggest that increases in LVMI and decreases in LVEF coincide with advances in CKD stages in patients with diabetes.

Echocardiographic parameters are independently associated with increased cardiovascular events in patients with chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) are associated with increased cardiovascular (CV) morbidity and mortality. Echocardiographic measures of heart structure and function have been reported to predict adverse CV outcomes in various pathologic conditions. The aim of this study is to assess whether echocardiographic parameters are independently associated with increased CV events in patients with CKD Stages 3-5.

METHODS

We consecutively enrolled 505 CKD patients from our outpatient department of internal medicine. CV events were defined as CV death, hospitalization for unstable angina, non-fatal myocardial infarction, sustained ventricular arrhythmia, hospitalization for congestive heart failure, transient ischemia attack and stroke. The relative CV events' risk was analyzed by Cox regression methods.

RESULTS

In the multivariate analysis, old age, the presence of diabetes, coronary artery disease and atrial fibrillation; decreased serum albumin and hematocrit levels; left atrial diameter (LAD) >4.7 cm [hazard ratio (HR), 2.141; 95% confidence interval (CI), 1.155-3.971, P = 0.016]; increased left ventricular mass index (LVMI) (HR, 1.006; 95% CI, 1.002 to 1.010, P = 0.003) and left ventricular ejection fraction (LVEF) <55% (HR, 2.007; 95% CI, 1.007-3.743, P = 0.028) were independently associated with increased CV events.

CONCLUSIONS

Our findings show that LAD >4.7 cm, increased LVMI and LVEF <55% are independently associated with adverse CV outcomes in CKD patients. Screening CKD patients by means of echocardiography may help identify a high-risk group of poor CV prognosis.

Allopurinol benefits left ventricular mass and endothelial dysfunction in chronic kidney disease

Allopurinol ameliorates endothelial dysfunction and arterial stiffness among patients without chronic kidney disease (CKD), but it is unknown if it has similar effects among patients with CKD. Furthermore, because arterial stiffness increases left ventricular afterload, any allopurinol-induced improvement in arterial compliance might also regress left ventricular hypertrophy (LVH). We conducted a randomized, double-blind, placebo-controlled, parallel-group study in patients with stage 3 CKD and LVH. We randomly assigned 67 subjects to allopurinol at 300 mg/d or placebo for 9 months; 53 patients completed the study. We measured left ventricular mass index (LVMI) with cardiac magnetic resonance imaging (MRI), assessed endothelial function by flow-mediated dilation (FMD) of the brachial artery, and evaluated central arterial stiffness by pulse-wave analysis. Allopurinol significantly reduced LVH (P=0.036), improved endothelial function (P=0.009), and improved the central augmentation index (P=0.015). This study demonstrates that allopurinol can regress left ventricular mass and improve endothelial function among patients with CKD. Because LVH and endothelial dysfunction associate with prognosis, these results call for further trials to examine whether allopurinol reduces cardiovascular events in patients with CKD and LVH.

Reversible cardiomyopathies--a review

End-stage renal disease, cirrhosis, obesity, tachycardia, and extreme stress have all been shown to result in impaired left ventricular function. It is becoming clear, however, that the cardiomyopathies associated with these states are reversible after resolution of the underlying process. In this article, we present the current data demonstrating that renal transplantation, liver transplantation, and bariatric surgery can lead to reversal of uremic, cirrhotic, and obesity cardiomyopathies, respectively. We also discuss the reversibility of tachycardia-induced cardiomyopathy after radiofrequency ablation or pharmacologic therapy for rate or rhythm control and the reversibility of stress-induced cardiomyopathy with supportive care.

Sudden cardiac death in chronic kidney disease: epidemiology and prevention

Annual cardiovascular mortality in patients with chronic kidney disease (CKD) is much higher than in the general population. The rate of sudden cardiac death increases as the stage of CKD increases and could be responsible for 60% of cardiac deaths in patients undergoing dialysis. In hemodialysis units treating patients with CKD, cardiac arrest occurs at a rate of seven arrests per 100,000 hemodialysis sessions. Important risk factors for sudden cardiac death in patients with CKD include hospitalization within the past 30 days, a drop of 30 mmHg in systolic blood pressure during hemodialysis, duration of life on hemodialysis, time since the previous dialysis session, and the presence of concomitant diabetes mellitus. As a result of the adverse cardiomyopathic and vasculopathic milieu in CKD, the occurrence of arrhythmias, conduction abnormalities, and sudden cardiac death could be exacerbated by electrolyte shifts, divalent ion abnormalities, diabetes, sympathetic overactivity, in addition to inflammation and perhaps iron deposition. Impaired baroreflex effectiveness and sensitivity, as well as obstructive sleep apnea, might also contribute to the risk of sudden death in CKD. The likelihood of survival following cardiac arrest is very low in dialysis patients. Primary and secondary prevention of cardiac arrest could reduce cardiovascular mortality in patients with CKD. Cardioverter-defibrillator implantation decreases the risk of sudden death in patients with CKD. The decision to implant a cardioverter-defibrillator should be influenced by the patient's age and stage of CKD.

Cardiovascular disease in renal transplant recipients

Renal transplant recipients have a markedly increased risk of premature cardiovascular disease (CVD) compared with the general population, although considerably lower than that of patients receiving maintenance haemodialysis. CVD in transplant recipients is poorly characterised and differs from the nonrenal population, with a much higher proportion of fatal to nonfatal cardiac events. In addition to traditional ischaemic heart disease risk factors such as age, gender, diabetes and smoking, there are additional factors to consider in this population such as the importance of hypertension, left ventricular hypertrophy and uraemic cardiomyopathy. There are factors specific to transplantation such immunosuppressive therapies and graft dysfunction which contribute to this altered risk profile. However, understanding and treatment is limited by the absence of large randomised intervention trials addressing risk factor modification, with the exception of the ALERT study. The approach to managing these patients should begin early and be multifactorial in nature.