Lavanya Srinivasan

Renin angiotensin system blockade and cardiovascular outcomes in patients with chronic kidney disease and proteinuria: A meta-analysis

OBJECTIVE The role of renin angiotensin system (RAS) blockade in controlling hypertension and the positive impact on cardiovascular (CV) outcomes is well known. However, the role of RAS blockade in improving CV outcomes in patients with chronic kidney disease (CKD) is still unclear. METHODS Randomized controlled trials that analyzed CV outcomes in patients with CKD/proteinuria treated with RAS blockade (angiotensin-converting enzyme inhibitors/angiotensin receptor blockers) were included in our study. The relative risk across all study groups was computed using Mantel-Hanszel random effects model. Results were calculated with 95% CI and was considered statistically significant if 2-sided alpha error was <.05. Renin angiotensin system blockade-based therapy was compared with placebo and control (beta-blocker, calcium-channel blockers and other antihypertensive-based therapy) therapy in the study. RESULTS Twenty-five trials (N = 45758) were used for analysis. Renin angiotensin system blockade decreased the risk for heart failure in patients with diabetic nephropathy when compared with placebo 0.78 (95% CI 0.66-0.92, P = .003) and control therapy (0.63, 95% CI 0.47-0.86, P = .003). The risk for CV outcomes was decreased with RAS blockade (0.56, 95% CI 0.47-0.67, P < .001) in nondiabetic nephropathy patients with CKD when compared with control therapy. There was also a significant reduction of CV outcomes (0.84, 95% CI 0.78-0.91, P < .0001), myocardial infarction (0.78, 95% CI 0.65-0.97, P = .03), and heart failure (0.74, 95% CI 0.58-0.95, P = .02) when we pooled all the patients with CKD and compared RAS blockade to placebo. CONCLUSIONS A pooled analysis of all causes of CKD revealed a reduction in the risk for myocardial infarction, heart failure, and total CV outcomes when RAS blockade was compared with placebo. RAS blockade decreases the risk for CV outcomes and heart failure when compared with control therapy in patients with proteinuria. There were also benefits with RAS blockade in reducing the risk of CV outcomes and heart failure in patients with diabetic nephropathy when compared with placebo.

Effect of yoga in chronic obstructive pulmonary disease.

Yoga is adjunctively utilized outside the United States in the treatment of a variety of diseases, including chronic obstructive pulmonary disease (COPD), but there are no studies assessing its adjunctive efficacy in the United States. We prospectively evaluated the effects of yoga training on the quality of life (QOL) and the parameters of lung function in patients with COPD. Thirty-three patients with documented COPD, per Global Initiative for Obstructive Lung Disease criteria, were recruited. All patients received standard COPD care. The QOL was assessed by the St. George Respiratory questionnaire. Standard spirometry and maximum inspiratory (maximal inspiratory pressure) and expiratory pressure (maximal expiratory pressure) were measured. Patients were taught selected yoga exercises including breathing exercises, meditation, and yoga postures for 1 hour, thrice a week for 6 weeks by a certified yoga therapist. The quality of life and lung function were again assessed at the end of 6 weeks. Twenty-two patients completed the study. Differences in preyoga versus postyoga scores were evaluated using paired t-tests. Statistically significant improvements (P < 0.05) were observed for the St. George Respiratory questionnaire [95% confidence interval (CI) 43.13–58.47], vital capacity (95% CI 2.53–7.65), maximal inspiratory pressure (95% CI 6.62–23.64), and maximal expiratory pressure (95% CI 1.63–13.81). Yoga when practiced by patients with COPD results in improvement in the QOL and lung function on a short-term basis. Additional research is needed to confirm these findings in a randomized controlled trial and in the longer term.

Effect of Visualization of Raw Graphic Polysomnography Data by Sleep Apnea Patients on Adherence to CPAP Therapy

BACKGROUND: CPAP is considered to be the cornerstone of therapy for obstructive sleep apnea. However, adherence to this treatment is frequently poor, which may lead to ongoing symptoms, including daytime sleepiness and poor cognitive function. We aimed to determine the efficacy of showing patients their raw graphic polysomnography (PSG) data in increasing their CPAP adherence. METHODS: The subjects were patients with obstructive sleep apnea (n = 37, diagnosed on prior PSG), who were prospectively randomized into an experimental arm or a control arm. The patients in the experimental arm (n = 18) were shown detailed PSG data, including graphic data from PSG prior to prescription of CPAP. The patients in the control arm (n = 19) were shown the non-graphic paper report of the PSG. Adherence data, collected using CPAP devices with internal microprocessors (adherence cards), was read at 4 weeks after treatment initiation. RESULTS: There was no difference in age (57.3 ± 11.8 y vs 55.5 ± 11.6 y, P = .64), body mass index (BMI) (32.7 ± 6.3 kg/m2 vs 32.3 ± 6.6 kg/m2, P = .85), and apnea-hypopnea index (36.0 ± 27.8 events/h vs 30.5 ± 19.1 events/h, P = .48) between the experimental and control arms. There was no difference in percent of days CPAP was used (58% vs 64%, P = .59) and average number of hours each night CPAP was used (3.9 ± 2.1 h vs 4.1 ± 2.5 h, P = .76) between the experimental and control arms, respectively. In multi logistic regression models, which included age, BMI > 30 kg/m2, apnea-hypopnea index, and experimental intervention, only BMI was found to increase likelihood of improved adherence (odds ratio = 13.3, P = .007). CONCLUSIONS: Showing patients raw graphic PSG data does not seem to improve adherence to CPAP. BMI is a very strong predictor of CPAP adherence.

Clinical utility of cardiac troponin i in the diagnosis of acute coronary syndrome in patients with renal failure

To analyze sensitivity and specificity of cardiac troponin I (cTnI) in detecting obstructive coronary artery disease in African American population with renal insufficiency presenting with acute coronary syndrome. Retrospective analysis of 108 patients who underwent coronary angiography over a 3-year period in a single institution. A troponin I level of 0.1 ng/mL or higher was considered abnormal troponin I. Renal insufficiency was defined as creatinine of 1.2 mg/dL or higher. Obstructive coronary artery disease (CAD) was defined as luminal diameter reduction of 70% or more (or total occlusion) in at least 1 coronary artery. Patients were divided into group 1 (renal insufficiency without need for hemodialysis, n = 76, mean age = 65) and group 2 (patients requiring hemodialysis, n = 32, mean age = 60). Access Accu TnI method was used to quantitate cTnI where murine monoclonal antibodies specifically bind to the C-terminal end of cTnI. In group 1, 41 (54%) patients had abnormal troponin of whom 37 (90%) had CAD and 4 (10%) had normal angiogram; 35 (46%) patients had normal troponin, of whom 25 (71%) had CAD and 10 (29%) had normal angiogram yielding a sensitivity of 60% and specificity of 71% (P = 0.003; 95% confidence interval). In group 2, 20 (63%) had abnormal troponin of whom 19 (95%) had CAD and 1(5%) had normal angiogram; 12 (38%) had normal troponin of whom 7 (59%) had CAD and 5 (41%) had normal angiogram yielding a sensitivity of 73% and specificity of 83% (P = 0.06; 95% confidence interval). cTnI has a sensitivity of 60% and specificity of 71% in acute coronary syndrome patients with renal insufficiency. In patients on hemodialysis, troponin I has a sensitivity of 73% and specificity of 83% for detection of obstructive CAD.