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Dive into the research topics where Ritam Chowdhury is active.

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Featured researches published by Ritam Chowdhury.


The Annals of Thoracic Surgery | 2012

Risk Factors for Conversion to Cardiopulmonary Bypass During Off-Pump Coronary Artery Bypass Surgery

Ritam Chowdhury; Darcy White; Patrick D. Kilgo; John D. Puskas; Vinod H. Thourani; Edward P. Chen; Omar M. Lattouf; William A. Cooper; Richard J. Myung; Robert A. Guyton; Michael E. Halkos

BACKGROUND Off-pump coronary artery bypass graft (OPCAB) may be associated with improved hospital outcomes compared with on-pump coronary artery bypass graft. However, intraoperative conversion to on-pump coronary artery bypass graft has been associated with adverse outcomes. The purpose of this study was to identify preoperative risk factors for intraoperative conversion in nonemergent patients undergoing isolated OPCAB. METHODS From 2002 to 2010, 8,077 consecutive OPCAB cases were performed at a single US academic center. Of these, 200 (2.5%) required intraoperative conversion. Standard variables from The Society of Thoracic Surgeons database were analyzed. A multivariable logistic model with adjusted odds ratios (OR) and 95% confidence intervals was used to identify independent risk factors for conversion. Adjusted in-hospital and long-term survival between converted and nonconverted patients were determined using multiple logistic regression and Cox proportional hazards regression, respectively. RESULTS Converted patients had a higher Society of Thoracic Surgeons predicted risk of mortality (2.8% versus 2.1%; p<0.001). Surgeon identity was the most significant multivariable predictor of conversion. After adjustment for surgeon identity, the following independent risk factors were associated with intraoperative conversion: previous coronary artery bypass graft (OR, 3.43; p=0.018), congestive heart failure (OR, 1.51), myocardial infarction (OR, 1.86), number of grafts (OR, 1.45), left main disease (OR 1.41), and urgent status (OR, 1.77; all p<0.05). Conversion to on-pump coronary artery bypass graft was associated with increased in-hospital (OR, 4.8; p<0.001) and long-term mortality (hazard ratio, 1.65; p<0.001). CONCLUSIONS Conversion to cardiopulmonary bypass during OPCAB is associated with increased in-hospital and long-term mortality and may be related to surgeon experience. Recognition of the preoperative risk factors associated with an increased risk of conversion may allow for better patient selection and reduce the incidence of intraoperative conversion during OPCAB.


The Annals of Thoracic Surgery | 2013

The Impact of Specific Preoperative Organ Dysfunction in Patients Undergoing Aortic Valve Replacement

Vinod H. Thourani; Ritam Chowdhury; Rebecca L. Gunter; Patrick D. Kilgo; Edward P. Chen; John D. Puskas; Michael E. Halkos; Omar M. Lattouf; William A. Cooper; Robert A. Guyton

BACKGROUND Optimizing treatment strategies to risk profile patients undergoing aortic valve replacement remains a priority. The role that specific and combinations of preoperative organ dysfunction (OD) plays in informing these decisions remains uncertain. This study sought to determine the relative effect that OD in particular systems has on short- and long-term outcomes. METHODS A total of 1,759 aortic valve replacement cases with and without coronary artery bypass grafting performed from January 2002 to June 2010 at Emory University are the basis for this retrospective analysis. Patients were classified by the presence or absence of preoperative OD: (1) cardiac: congestive heart failure (ejection fraction <0.35), (2) pulmonary: forced expiratory volume in 1 second less than 50% predicted, (3) neurologic (prior stroke), and (4) renal: chronic renal failure. The impact of individual and combined OD on outcomes was evaluated. Kaplan-Meier survival estimates and Cox regression models were used to assess the relationship between OD and long-term survival. RESULTS A total of 513 patients (29.2%) had at least one OD, including 95 patients (5.4%) with more than one OD. Organ dysfunction in each organ system was associated with poorer survival. Renal (hazard ratio, 3.90) and pulmonary (hazard ratio, 2.40) OD patients had poorer long-term survival, including 30-day mortality. Seven-year survival for OD patients is as follows: prior stroke, 48.6%; severe chronic obstructive pulmonary disease, 30.8%; congestive heart failure, 55.9%; and chronic renal failure, 11.7%. The sequential addition of OD systems was a powerful predictor of poorer long-term survival. CONCLUSIONS The presence of chronic renal failure most profoundly decreases survival, followed by severe chronic obstructive pulmonary disease and prior stroke. Furthermore, multiple OD systems significantly decrease short- and long-term survival.


Clinical Endocrinology | 2014

Vitamin D status is independently associated with plasma glutathione and cysteine thiol/disulphide redox status in adults

Jessica A. Alvarez; Ritam Chowdhury; Dean P. Jones; Greg S. Martin; Kenneth L. Brigham; Jose Binongo; Thomas R. Ziegler; Vin Tangpricha

Redox status and inflammation are important in the pathophysiology of numerous chronic diseases. Epidemiological studies have linked vitamin D status to a number of chronic diseases. We aimed to examine the relationships between serum 25‐hydroxyvitamin D [25(OH)D] and circulating thiol/disulphide redox status and biomarkers of inflammation.


Journal of the American Heart Association | 2014

Consumption of less than 10% of total energy from added sugars is associated with increasing HDL in females during adolescence: a longitudinal analysis.

Alexandra K. Lee; Jose Binongo; Ritam Chowdhury; Aryeh D. Stein; Julie A. Gazmararian; Miriam B. Vos; Jean A. Welsh

Background Atherosclerotic changes associated with dyslipidemia and increased cardiovascular disease risk are believed to begin in childhood. While previous studies have linked added sugars consumption to low high‐density lipoprotein (HDL), little is known about the long‐term impact of this consumption. This study aims to assess the association between added sugars intake and HDL cholesterol levels during adolescence, and whether this association is modified by obesity. Methods and Results We used data from the National Heart Lung and Blood Institutes Growth and Health Study, a 10‐year cohort study of non‐Hispanic Caucasian and African‐American girls (N=2379) aged 9 and 10 years at baseline recruited from 3 sites in 1987‐1988 with biennial plasma lipid measurement and annual assessment of diet using a 3‐day food record. Added sugars consumption was dichotomized into low (0% to <10% of total energy) and high (≥10% of total energy). In a mixed model controlling for obesity, race, physical activity, smoking, maturation stage, age, and nutritional factors, low compared with high added sugar consumption was associated with a 0.26 mg/dL greater annual increase in HDL levels (95% CI 0.48 to 0.04; P=0.02). Over the 10‐year study period, the model predicted a mean increase of 2.2 mg/dL (95% CI 0.09 to 4.32; P=0.04) among low consumers, and a 0.4 mg/dL decrease (95% CI −1.32 to 0.52; P=0.4) among high consumers. Weight category did not modify this association (P=0.45). Conclusion Low added sugars consumption is associated with increasing HDL cholesterol levels throughout adolescence.


Obesity science & practice | 2015

Sugars and adiposity: the long-term effects of consuming added and naturally occurring sugars in foods and in beverages.

A.K. Lee; Ritam Chowdhury; Jean A. Welsh

The aim of this study was to determine if the association with adiposity varies by the type (added vs. naturally occurring) and form (liquid vs. solid) of dietary sugars consumed.


Kidney International | 2015

Geographic variation and neighborhood factors are associated with low rates of pre–end-stage renal disease nephrology care

Hua Hao; Brendan P. Lovasik; Stephen O. Pastan; Howard H. Chang; Ritam Chowdhury; Rachel E. Patzer

Geographic variation of pre-end-stage renal disease (pre-ESRD) nephrology care has not been studied across the United States. Here we sought to identify geographic differences in pre-ESRD care, assess for county-level geographic and sociodemographic risk factors, and correlate with patient outcomes using facility-level mortality. Patients from 5387 dialysis facilities across the United States from 2007 to 2010 were included from the Dialysis Facility Report. Marginal generalized estimating equations were used for modeling with geographic cluster analysis to detect clusters of facilities with low rates of pre-ESRD care. On average, 67% of patients received pre-ESRD care in the United States but with significant variability across regions ranging from 3 to 99%. Five geographic clusters of facilities with low rates of pre-ESRD care were the metropolitan areas of San Francisco, Los Angeles, Chicago, Miami, and Baltimore, along with Southern states along the Mississippi River. Dialysis facilities with the lowest rates of pre-ESRD care were more likely to be located in urban counties with high African-American populations and low educational attainment. A 10% higher proportion of patients receiving pre-ESRD care was associated with 1.3% lower patient mortality as reflected by facility-level mortality. Thus, geographic and sociodemographic factors can be used to design quality improvement initiatives to increase access to nephrology care nationwide and improve patient outcomes.


Nutrition in Clinical Practice | 2014

Relationship Between Fat-Soluble Vitamin Supplementation and Blood Concentrations in Adolescent and Adult Patients With Cystic Fibrosis.

Oranan Siwamogsatham; Wei Dong; Jose Binongo; Ritam Chowdhury; Jessica A. Alvarez; Shawna J. Feinman; Jessica Enders; Vin Tangpricha

Background: Pancreatic insufficiency is common in patients with cystic fibrosis (CF) and leads to malabsorption of fat-soluble vitamins. Multivitamins, including vitamins A, D, E, and K, are routinely prescribed to patients with CF to prevent vitamin deficiencies. Our objective was to examine the relationship between fat-soluble vitamin supplements and their impact on blood concentrations. Methods: This was a retrospective chart review of patients with CF who were treated at Emory Clinic and Emory University Hospital during 2008-2012. The amount of fat-soluble vitamin supplementation, serum markers of fat-soluble vitamin concentrations, CF transmembrane conductance regulator genotype, and other demographic information were recorded from electronic medical records. Mixed-effects models were used to investigate the trends over time of fat-soluble vitamin supplements and serum vitamin concentrations. Results: In total, 177 charts were eligible. Mean (SD) age was 26.1 (10.2) years. Ninety-two percent of patients had pancreatic insufficiency and 52% had the homozygous ΔF508 mutation. Recorded fat-soluble vitamin supplementation increased in the past 5 years (P < .001 for all). Serum 25-hydroxyvitamin D increased slightly (3% increase; P < .01); however, there were no changes in the blood concentrations of vitamins A, E, and K (P = .26-.96). Conclusions: Despite a near doubling of recorded fat-soluble vitamin supplementation over the past 5 years, there was no parallel increase in blood concentrations of these vitamins. Potential reasons include suboptimal dosages, low adherence, or ongoing issues with malabsorption.


BMJ | 2015

What are the consequences when doctors strike

David Metcalfe; Ritam Chowdhury; Ali Salim

Doctors considering strike action may worry about the effect on patients. David Metcalfe and colleagues examine the evidence


The Journal of Pediatrics | 2017

Factors associated with pediatric mortality from motor vehicle crashes in the United States: a state-based analysis

Lindsey L. Wolf; Ritam Chowdhury; Jefferson Tweed; Lori Vinson; Elena Losina; Adil H. Haider; Faisal G. Qureshi

OBJECTIVE To examine geographic variation in motor vehicle crash (MVC)-related pediatric mortality and identify state-level predictors of mortality. STUDY DESIGN Using the 2010-2014 Fatality Analysis Reporting System, we identified passengers <15 years of age involved in fatal MVCs, defined as crashes on US public roads with ≥1 death (adult or pediatric) within 30 days. We assessed passenger, driver, vehicle, crash, and state policy characteristics as factors potentially associated with MVC-related pediatric mortality. Our outcomes were age-adjusted, MVC-related mortality rate per 100 000 children and percentage of children who died of those in fatal MVCs. Unit of analysis was US state. We used multivariable linear regression to define state characteristics associated with higher levels of each outcome. RESULTS Of 18 116 children in fatal MVCs, 15.9% died. The age-adjusted, MVC-related mortality rate per 100 000 children varied from 0.25 in Massachusetts to 3.23 in Mississippi (mean national rate of 0.94). Predictors of greater age-adjusted, MVC-related mortality rate per 100 000 children included greater percentage of children who were unrestrained or inappropriately restrained (P < .001) and greater percentage of crashes on rural roads (P = .016). Additionally, greater percentages of children died in states without red light camera legislation (P < .001). For 10% absolute improvement in appropriate child restraint use nationally, our risk-adjusted model predicted >1100 pediatric deaths averted over 5 years. CONCLUSIONS MVC-related pediatric mortality varied by state and was associated with restraint nonuse or misuse, rural roads, vehicle type, and red light camera policy. Revising state regulations and improving enforcement around these factors may prevent substantial pediatric mortality.


American Journal of Preventive Medicine | 2017

Exercise Capacity, Heart Failure Risk, and Mortality in Older Adults: The Health ABC Study

Vasiliki V. Georgiopoulou; Andreas P. Kalogeropoulos; Ritam Chowdhury; Jose Binongo; Kirsten Bibbins-Domingo; Nicolas Rodondi; Eleanor M. Simonsick; Tamara B. Harris; Anne B. Newman; Stephen B. Kritchevsky; Javed Butler

INTRODUCTION Data on the association between exercise capacity and risk for heart failure (HF) in older adults are limited. METHODS This study examined the association of exercise capacity, and its change over time, with 10-year mortality and incident HF in 2,935 participants of the Health, Aging, and Body Composition Study without HF at baseline (age, 73.6 [SD=2.9] years; 52.1% women; 41.4% black; 58.6% white). This cohort was initiated in 1997-1998 and exercise capacity was evaluated with a long-distance corridor walk test (LDCW) at baseline and Year 4. Outcomes were collected in 2007-2008 and initial analysis performed in 2014. RESULTS Ten-year incident HF for completers (n=2,245); non-completers (n=331); and those excluded from LDCW for safety reasons (n=359) was 11.4%, 19.2%, and 23.0%, respectively. The corresponding 10-year mortality was 27.9%, 41.1%, and 42.4%. In models accounting for competing mortality, the adjusted subhazard ratio for HF was 1.37 (95% CI=1.00, 1.88; p=0.049) in non-completers and 1.41 (95% CI=1.06, 1.89; p=0.020) in those excluded versus completers. Non-completers (adjusted hazard ratio, 1.49; 95% CI=1.21, 1.84; p<0.001) and those excluded (hazard ratio, 1.27; 95% CI=1.04, 1.55; p=0.016) had elevated mortality. In adjusted models, LDCW performance variables were associated mainly with mortality. Only 20-meter walking speed and resting heart rate retained prognostic value for HF. Longitudinal changes in LDCW did not predict subsequent incident HF or mortality. CONCLUSIONS Completing an LDCW is strongly associated with lower 10-year mortality and HF risk in older adults. Therefore, walking capacity may serve as an early risk marker.

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Adil H. Haider

Brigham and Women's Hospital

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Wei Jiang

Brigham and Women's Hospital

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