Vijaiganesh Nagarajan

Obesity paradox in heart failure: a heavy matter

Obesity and heart failure are two of the leading causes of morbidity and mortality in the world. The relationship between obesity and cardiovascular diseases is complex and not fully understood. While the risk of developing heart failure has been shown to be higher in patients who are obese, there is a survival advantage for obese and overweight patients compared with normal weight or low weight patients. This phenomenon was first described by Horwich et al. and was subsequently confirmed in other large trials. The advantage exists irrespective of the type, aetiology, or stage of heart failure. Patients with morbid obesity (body mass index >40 kg/m2), however, do not have the same survival advantage of their obese counterparts. There are several alternative indices of obesity available that may be more accurate than body mass index. The role of weight loss in patients with heart failure is unclear; thus, providing sound clinical advice to patients remains difficult. Future prospective trials designed to evaluate the link between obesity and heart failure will help us understand more fully this complex relationship.

Seasonal and circadian variations of acute myocardial infarction: Findings from the Get With The Guidelines–Coronary Artery Disease (GWTG-CAD) program

Background Seasonal variation with winter preponderance of myocardial infarction incidence has been described decades ago, but only a few small studies have classified myocardial infarction based on ST‐segment elevation. It is unclear whether seasonal and circadian variations are equally present in warmer and colder regions. We investigated whether seasonal and circadian variations in acute myocardial infarction (AMI) are more prominent in colder northern states compared with warmer southern states. We also investigated the peak time of admission to better understand the circadian rhythm. Methods Data from the GWTG‐CAD database were used. We analyzed 82,971 consecutive acute myocardial infarction (AMI) patients treated at 276 US centers from 2003 to 2008. The country was geographically divided into warmer southern and colder northern states using latitude 35 degrees for this purpose. Results Overall, acute myocardial infarction (AMI) admissions varied across seasons (P < .01), and were higher in winter (winter vs. spring n = 21,483 vs. 20,291, respectively). When stratified based on type of AMI, non–ST‐segment elevation myocardial infarction (NSTEMI) admissions varied across seasons (P < .01) and were highest in winter and lowest in spring. Seasonal variation was not significant in STEMI admissions (P = .30). Seasonal variation with winter predominance was noted in AMI patients in warmer southern states (P < .01), but not in colder states. The distributions of length of stay for AMI patients and door to balloon times for STEMI patients were minimally different across all four seasons (P < .01) with longest occurring in winter. Most patients with AMI presented during daytime with a peak close to 11 am and a nadir at approximately 4 am. Conclusions Seasonal variation with winter predominance exists in AMI admissions and was significant in NSTEMI admissions but not in STEMI admissions. Seasonal variation was only significant in warmer southern states.

Obesity paradox in group 1 pulmonary hypertension: analysis of the NIH-Pulmonary Hypertension registry

Background:The ‘obesity paradox’ refers to the fact that obese patients have better outcomes than normal weight patients. This has been observed in multiple cardiovascular conditions, but evidence for obesity paradox in pulmonary hypertension (PH) remains sparse.Methods:We categorized 267 patients from the National Institute of Health-PH registry into five groups based on body mass index (BMI): underweight, normal weight, overweight, obese and morbidly obese. Mortality was compared in BMI groups using the χ2 statistic. Five-year probability of death using the PH connection (PHC) risk equation was calculated, and the model was compared with BMI groups using Cox proportional hazards regression and Kaplan–Meier (KM) survival curves.Results:Patients had a median age of 39 years (interquartile range 30–50 years), a median BMI of 23.4 kg m−2 (21.0–26.8 kg m−2) and an overall mortality at 5 years of 50.2%. We found a U-shaped relationship between survival and 1-year mortality with the best 1-year survival in overweight patients. KM curves showed the best survival in the overweight, followed by obese and morbidly obese patients, and the worst survival in normal weight and underweight patients (log-rank P=0.0008). In a Cox proportional hazards analysis, increasing BMI was a highly significant predictor of improved survival even after adjustment for the PHC risk equation with a hazard ratio for death of 0.921 per kg m−2 (95% confidence interval: 0.886–0.954) (P<0.0001).Conclusion:We observed that the best survival was in the overweight patients, making this more of an ‘overweight paradox’ than an ‘obesity paradox’. This has implications for risk stratification and prognosis in group 1 PH patients.

Usefulness of cell-mediated immune function in risk stratification for patients with advanced heart failure

Background Although heightened inflammation and autoimmune responses have been well described in patients with heart failure, the role of cell‐mediated immune function in the pathogenesis and progression of heart failure is unclear. The aim of our study is to evaluate the prognostic role of cell‐mediated immune function in patients with advanced heart failure. Methods We studied patients with advanced heart failure referred for evaluation of candidacy for advanced heart failure therapies between 2007 and 2010. Cell‐mediated immune response was categorized into 3 groups—low or poor immune response (≤225 ng/mL), moderate or normal immune response (226‐524 ng/mL), and strong immune response (≥525 ng/mL)—using a phytohemagglutinin‐stimulated T‐cell response assay. Results Out of 368 patients, 41 patients (11.1%) had poor immune function, 258 patients (70.1%) had normal immune function, and 69 patients (18.7%) had strong immune function. The primary outcome of all‐cause mortality or cardiac transplantation occurred in 63.4%, 45.3%, and 34.8% in the poor immunity, normal immunity, and strong immune function groups, respectively. In univariate analysis, cell‐mediated immune function was strongly associated with the primary outcome (P = .014). Poor immune function portended worse prognosis (hazard ratio = 2.18, 95% CI 1.01‐4.70, P = .047), and strong immune function was associated with better survival (hazard ratio = 0.67, 95% CI 0.43‐1.04). However, when adjusted for multiple variables in multivariate analysis, immune function status lost its overall significance to predict primary outcome (P = .11), but the direction to an increased risk of primary outcome was maintained in the poor immune function group. Conclusions Poor cell‐mediated immune function measured by a clinically available assay could be associated with more adverse long‐term prognosis in patients with advanced heart failure.

A 70-year-old woman with heart failure with preserved ejection fraction

See also page [518][1] and [www.cmaj.ca/lookup/doi/10.1503/cmaj.140430][2] A 70-year-old woman was referred to her family physician by the emergency department for follow-up of shortness of breath, orthopnea and swelling of her legs that she had experienced for two months. She had no other symptoms

Pleural Effusion from Leaky Diaphragm—the Hepatic Hydrothorax

A 76-year-old woman with liver cirrhosis presented with six weeks of progressive shortness of breath, and was found to have a large right pleural effusion with minimal ascites. Echocardiogram showed normal left ventricular ejection fraction. The portal venous system was patent by Doppler ultrasound. Pleural fluid analysis revealed a transudative effusion without evidence of infection or malignancy. Despite drainage and diuretics, her effusion recurred. When technetium was injected into the peritoneal cavity for nuclear imaging, there was strong uptake in the perihepatic fluid collection and diffuse uptake into the right hemithorax, suggesting a peritoneo-pleural communication, confirming the diagnosis of hepatic hydrothorax (Figs. 1 and 2). The patient underwent a transjugular intrahepatic portosystemic shunt (TIPS) procedure with improvement of symptoms. Hepatic hydrothorax is a complication of portal hypertension and usually affects the right side of the chest. Leakage of fluid from the peritoneal to the pleural cavity through sub-centimeter diaphragmatic defects is the likely mechanism. Once cardiopulmonary causes of effusion are excluded, the investigation of choice is radioisotope-based nuclear imaging. Chest tube placement should not be performed, as it can cause large amounts of fluid loss, leading to renal failure and even death. TIPS procedure is recommended in diuretic resistant patients with recurrent effusions, although eventually a liver transplantation should be considered.

Q: Can an ARB be given to patients who have had angioedema on an ACE inhibitor?

Proceed with caution. ARBs can also cause angioedema, but the benefit may outweigh the risk if the patient truly needs the drug.

Impact of around-the-clock in-house cardiology fellow coverage on door-to-balloon time in an academic medical center

Objectives To assess if a change in our cardiology fellowship program impacted our ST elevation myocardial infarction (STEMI) program. Background Fellows covering the cardiac care unit were spending excessive hours in the hospital while on call, resulting in increased duty hours violations. A night float fellow system was started on July 1, 2012, allowing the cardiac care unit fellow to sign out to a night float fellow at 5:30 pm. The night float fellow remained in-house until the morning. Methods We performed a retrospective study assessing symptom onset to arrival, arterial access to first device, and door-to-balloon (D2B) times, in consecutive STEMI patients presenting to our emergency department before and after initiation of the night float fellow system. Results From 2009 to 2013, 208 STEMI patients presented to our emergency department and underwent primary percutaneous coronary intervention. There was no difference in symptom onset to arrival (150±102 minutes vs 154±122 minutes, p=0.758), arterial access to first device (12±8 minutes vs 11±7 minutes, p=0.230), or D2B times (50±32 minutes vs 52±34 minutes, p=0.681) during regular working hours. However, there was a significant decrease in D2B times seen during off-hours (72±33 minutes vs 49±15 minutes, p=0.007). There was no difference in in-hospital mortality (11% vs 8%, p=0.484) or need for intra-aortic balloon pump placement (7% vs 8%, p=0.793). Conclusion In academic medical centers, in-house cardiology fellow coverage during off-hours may expedite care of STEMI patients.

Initial electrocardiogram as determinant of hospital course in ST elevation myocardial infarction

A proportion of patients with ST elevation myocardial infarction (STEMI) have an initial electrocardiogram (ECG) that is nondiagnostic and are definitively diagnosed on a subsequent ECG. Our aim was to assess whether patients with a nondiagnostic initial ECG are different than those with a diagnostic initial ECG.

THE ELUSIVE INITIAL ELECTROCARDIOGRAM IN PATIENTS WITH ST-ELEVATION MYOCARDIAL INFARCTION

Some patients with ST-elevation myocardial infarction (STEMI) have an initial 12-lead electrocardiogram (ECG) that is not diagnostic for STEMI, but meet diagnostic criteria on a subsequent ECG. In these patients, if serial ECGs are not performed, the diagnosis of STEMI may be delayed or missed