Diagnosis and treatment of coronary artery disease in hemodialysis patients evaluated for transplant

MicroRNA regulators of vascular pathophysiology in chronic kidney disease

Coronary artery disease (CAD) is a severe comorbidity in chronic kidney disease (CKD) due to heavy calcification in the medial layer and inflamed plaques. Chronic inflammation, endothelial dysfunction and vascular calcification are major contributors that lead to artherosclerosis in CKD. The lack of specific symptoms and signs of CAD and decreased accuracy of noninvasive diagnostic tools result in delayed diagnosis leading to increased mortality. MicroRNAs (miRNAs) are post-transcriptional regulators present in various biofluids throughout the body. In the circulation, miRNAs have been reported to be encapsulated in extracellular vesicles and serve as stable messengers for crosstalk among cells. miRNAs are involved in pathophysiologic mechanisms including CAD and can potentially be extended from basic research to clinical translational practice.

Early cardiovascular events and cardiovascular death after renal transplantation: role of pretransplant risk factors

BACKGROUND

The purpose of this study was to verify the risk factors present in patients on the kidney transplant waiting list that may interfere with the incidence of cardiovascular (CV) events and death during the first 12 months after transplantation.

METHODS

Based on the data collected prospectively during pretransplant workups, a retrospective study was conducted including 665 patients followed up until death or completing 12 months posttransplantation. Endpoints were the composite incidence of CV events and death.

RESULTS

The prevalence of diabetes, LV hypertrophy, and CV disease at baseline was high; 14% of patients had angina, 26% an abnormal myocardial scan, and 47% coronary artery disease. CV events occurred in 53 patients (8.4%) and in 29 (55%) caused death. The independent predictors of events were age ≥ 50 years (HR 2.292; CI% 1.093-4.806), angina (HR 1.969; CI% 1.039-3.732), and altered myocardial scan (HR 1.905, CI% 1.059-3.428). Altered myocardial scan (HR 2.822, 95% CI 1.095-6.660) was also one of the independent predictor of CV death.

CONCLUSION

The incidence of CV events and death were predicted by variables associated with myocardial ischemia, a potentially modifiable risk factor. Patients with pretransplantation myocardial ischemia should be considered at a higher risk of developing early CV complications and managed accordingly before, during, and after kidney transplantation.

Prevalence and risk factors of coronary artery disease in patients with chronic viral hepatitis

OBJECTIVES

Patients with chronic viral hepatitis usually present metabolic abnormalities and hemodynamic changes, which are known factors associated with the development of coronary artery disease (CAD). This study aims to determine the risk factors of incident CAD in these patients.

METHODS

We identified 193 patients who subsequently developed CAD amongst 37,840 cases diagnosed as chronic viral hepatitis from January 2007 through December 2013.

RESULTS

In these patients, 141 had hepatitis B virus infections and 52 had hepatitis C virus infections. There was a male preponderance (65.9%). The median age at the diagnosis of hepatitis was 51 years. In the univariate analysis, patients aged ≥ 51 years had shorter median periods from the diagnosis of hepatitis to the onset of CAD than patients aged < 51 years (50 versus 96 months, p < 0.001), and patients with hypertension had shorter median durations compared to those without hypertension (48 versus 96 months, p < 0.001). Statistical significance also existed between patients with different etiologies (p = 0.004). In the multivariate analysis by Cox regression, age at the diagnosis of hepatitis (p < 0.001; hazard ratio (HR), 1.041; 95% CI, 1.027-1.056) and hypertension (with versus without, p < 0.001; HR, 1.925; 95% CI, 1.419-2.611) were revealed.

CONCLUSIONS

Age at diagnosis of hepatitis and hypertension appeared to be independent risk factors of incident CAD in these patients. This topic deserves further studies.

Hybrid myocardial imaging for risk stratification prior to kidney transplantation: added value of coronary calcium and epicardial adipose tissue

BACKGROUND

Patient selection and optimal approach to risk stratification prior to kidney transplantation remain uncertain. We sought new predictors of an abnormal myocardial perfusion (MYP) stress test result.

METHODS

Retrospective study of 411 consecutive chronic kidney disease stages 4-5D patients awaiting kidney transplantation referred for risk stratification. PET-CT or SPECT-CT was used to assess MYP and quantify coronary artery calcium (CAC) and epicardial adipose tissue (EAT). Abnormal MYP was defined as a perfusion defect involving ≥5% of the left ventricular myocardium.

RESULTS

Fixed or reversible MYP defects were present in 41 patients (10%). Male sex, smoking, and history of cardiovascular disease were more prevalent; age was higher and CAC and EAT were greater in patients with MYP defects than in those with normal MYP. On multivariate logistic regression, EAT and CAC were independent predictors of abnormal MYP while diabetes mellitus showed a borderline association (P = .08). EAT added incremental diagnostic value to a model including age, CAC and diabetes mellitus [AUC 0.73 (95% CI 0.64-0.81) to 0.76 (95% CI 0.68-0.84; P = .02)]. Furthermore, the model containing EAT showed improved diagnostic discrimination.

CONCLUSIONS

Abnormal MYP on screening stress testing appears to be rare in patients awaiting kidney transplantation suggesting an excess of testing. EAT and CAC may help predict what patients are at higher risk of developing abnormalities of MYP under stress.