Impaired coronary microcirculation is associated with left ventricular diastolic dysfunction in end-stage chronic kidney disease patients.

INTRODUCTION: Coronary vascular dysfunction, as assessed by coronary flow reserve (CFR) in the left anterior descending coronary artery, is found in various conditions including end-stage chronic kidney disease (CKD). Currently, we investigated the associations of CFR with echocardiographic indices of systolic and diastolic cardiac function and identified independent predictors of CFR in hemodialysis patients. METHODS: End-stage CKD patients treated with hemodialysis (n = 29) without known cardiovascular disease were recruited from a Hemodialysis Unit in Northwestern Greece. A thorough echocardiographic evaluation including CFR measurement following dipyridamole infusion was performed in all participants. Arterial stiffness was assessed by measurement of carotid-femoral pulse wave velocity and aortic augmentation index. RESULTS: The mean age of the patients was 63 years, and mean duration of hemodialysis was 2.9 years. CFR was 1.60 ± 0.37 while dipyridamole caused a significant increase in E'sep , Slat , E'lat , and Stroke volume (P < .05 for all). Independent predictors of CFR were posterior wall thickness (B -0.408, P = .013) and dipyridamole-induced changes in Tei index (B -0.425, P = .007). A severely decreased CFR < 1.5 was observed in 52% of the patients. E/E' ratio (B 10.84, P = .014) was the single independent predictor of severely decreased CFR. CONCLUSIONS: In end-stage CKD patients on hemodialysis without known cardiovascular disease, impaired coronary vascular function was prevalent and related to increased left ventricular wall thickness, increased filling pressures, and dipyridamole-induced deteriorated myocardial function independently of the presence of wall-motion abnormalities. Further studies are required to clarify the prognostic role of dipyridamole-induced cardiac changes in hemodialysis patients.

6-minute walking test: a useful tool in the management of heart failure patients.

Reduced functional ability and exercise tolerance in patients with heart failure (HF) are associated with poor quality of life and a worse prognosis. The 6-minute walking test (6MWT) is a widely available and well-tolerated test for the assessment of the functional capacity of patients with HF. Although the cardiopulmonary exercise test (a maximal exercise test) remains the gold standard for the evaluation of exercise capacity in patients with HF, the 6MWT (submaximal exercise test) may provide reliable information about the patient's daily activity. The current review summarizes the value of 6MWT in patients with HF and identifies its usefulness and limitations in everyday clinical practice in populations of HF. We aimed to investigate potential associations of 6MWD with other measures of functional status and determinants of 6MWD in patients with HF as well as to review its prognostic role and changes to various interventions in these patients.

The importance of characteristics of angina symptoms for the prediction of coronary artery disease in a cohort of stable patients in the modern era.

OBJECTIVE: Angina is an important clinical symptom indicating underlying coronary artery disease (CAD). Its characteristics are important for the diagnosis and risk stratification of patients with CAD. Currently, we aimed to investigate the association of chest pain characteristics with the presence of obstructive CAD in a contemporary cohort of patients undergoing coronary angiography for suspected stable CAD. METHODS: Consecutive patients undergoing coronary angiography for suspected stable CAD (n = 686) in a single university hospital cardiology department were enrolled. Chest pain was classified as typical angina, atypical angina, nonangina chest pain, and lack of symptoms. The presence of significant angiographic CAD was diagnosed by standard coronary angiography. RESULTS: Typical angina symptoms were associated with a higher prevalence of CAD (odds ratio [OR], 3.47, p < 0.001), whereas atypical angina symptoms were associated with a lower prevalence of CAD (OR, 0.49, p = 0.003) than the nonangina symptoms/or asymptomatic status. In multivariate analysis, typical angina symptoms remained an independent predictor of CAD (OR, 2.54, p < 0.001), with a greater predictive accuracy than other clinical risk factors (area under the curve [AUC], 0.715, p < 0.001) and similar to the accuracy of the high-sensitivity C-reactive protein (AUC, 0.712, p < 0.001). In a multivariate model, the combination of all studied factors further improved the predictive accuracy (AUC, 0.81, p < 0.001). CONCLUSION: In a contemporary cohort of patients referred for coronary angiography for stable CAD, the presence of typical angina symptoms was the most important independent predictor of obstructive CAD. The association of atypical angina symptoms with low CAD prevalence compared to nonangina chest pain or absence of significant symptoms probably reflects different management and referral strategies in these groups of patients.

Extent of coronary artery disease in patients undergoing angiography for stable or acute coronary syndromes.

BACKGROUND: We aimed to investigate whether the angiographic extent of coronary artery disease (CAD) differs in patients undergoing coronary angiography for stable CAD or acute coronary syndrome (ACS) and identify predictors of CAD extent in these patients. METHODS: We enrolled 584 consecutive patients (463 with stable CAD, 121 with ACS) with angiographically established CAD (≥1 stenosis >25%). The Gensini score was used to assess the extent of coronary atherosclerosis. RESULTS: Stable CAD patients had greater Framingham risk score and greater prevalence of hypertension, hypercholesterolemia, and diabetes (p<0.05 for all). Fasting glucose and systolic and diastolic blood pressure were higher, while high-sensitivity C-reactive protein (hsCRP) levels were lower in patients with stable CAD than in those with ACS (p<0.05 for all). No difference in Gensini score was observed between the two groups (p=0.118), but patients with ACS were more likely to have at least one significant epicardial angiographic lesion (>50% stenosis) (OR 2.0, p=0.022). Higher Gensini score was independently associated with (i) higher hsCRP and glucose levels, hypercholesterolemia, and increased age in stable CAD patients (R2 0.15, p<0001) and (ii) increased age and higher glucose and hsCRP levels in patients with ACS (R2 0.17, p<0001). CONCLUSIONS: Patients undergoing coronary angiography for ACS or stable CAD presented with a similar extent of angiographic CAD, although patients with ACS had a higher prevalence of significant lesions in the presence of a better cardiovascular risk profile and higher inflammation levels. The extent of angiographic CAD in both the groups shared common determinants such as hsCRP, age, and hyperglycemia, but these appeared to explain only a small part of the variation of coronary atherosclerosis.