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Dive into the research topics where Sam Radhakrishnan is active.

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Featured researches published by Sam Radhakrishnan.


Canadian Journal of Cardiology | 2016

Preprocedure Anemia Management Decreases Transfusion Rates in Patients Undergoing Transcatheter Aortic Valve Implantation

Mony Shuvy; Jumana Mewa; Rafael Wolff; Jordan Hutson; Peter C. Austin; Diane Bentley; Mark Iacovelli; Jeannie Callum; Sam Radhakrishnan; Stephen E. Fremes; Harindra C. Wijeysundera; Yulia Lin

BACKGROUNDnPeriprocedural blood transfusions are associated with long-term mortality in patients undergoing transcatheter aortic valve implantation (TAVI). We sought to assess the impact of a preoperative blood conservation approach in treating anemia and preventing blood transfusions in patients undergoing TAVI.nnnMETHODSnOur cohort consisted of all patients evaluated in our structural heart clinic between January 1, 2012 and December 31, 2014. From March 2013, all anemic TAVI candidates were referred to the blood conservation clinic (BCC). We evaluated the effectiveness of the program to increase hemoglobin levels and to decrease the blood transfusion rates in the TAVI cohort. A multivariable logistic regression model was used to evaluate the association of being assessed by the BCC with receipt of a blood transfusion.nnnRESULTSnThe cohort included 239 patients, 62% of whom were anemic. Beginning in March 2013, 60 patients were evaluated in the BCC and treated with intravenous/oral iron or subcutaneous epoetin alfa, or both. Patients who underwent blood conservation had a significant increase in hemoglobin levels from 10.8 ± 1.1 g/dL to 11.8xa0±xa01.2 g/dL (P < 0.001). Implementation of the BCC was associated with a substantial decrease in the average blood transfusion rate from 33.3% before program initiation to 15.3% after implementation (P < 0.001). After adjusting for baseline hemoglobin values and comorbidities, being assessed at the BCC was strongly associated with a reduction in the need for transfusion (odds ratio, 0.28; 95% confidence interval, 0.11-0.69; Pxa0= 0.006).nnnCONCLUSIONSnPreprocedural anemia management was successful in improving hemoglobin levels in anemic patients and in decreasing transfusion rates in TAVI.


BMC Cardiovascular Disorders | 2017

Factors associated with length of stay following trans-catheter aortic valve replacement - a multicenter study

Yaron Arbel; Nevena Zivkovic; Dhruven Mehta; Sam Radhakrishnan; Stephen E. Fremes; Effat Rezaei; Asim N. Cheema; Sami Alnasser; Ariel Finkelstein; Harindra C. Wijeysundera

BackgroundMost patients undergoing Transcatheter aortic valve implantation (TAVR) are elderly with significant co-morbidities and there is limited information available regarding factors that influence length of stay (LOS) post-procedure. The aim of this study was to identify the patient, and procedural factors that affect post-TAVR LOS using a contemporary multinational registry.MethodsWe conducted a retrospective cohort study, with patients recruited from three high volume tertiary institutions. The primary outcome was the LOS post-TAVR procedure. We examined patient and procedural factors in a cause-specific Cox multivariable regression model to elucidate their effect on LOS, accounting for the competing risk of post-procedural death. Hazard ratios (HR) greater than 1 indicate a shorter LOS, while HRs less than 1 indicate a longer LOS.ResultsThe cohort consisted of 809 patients. Patient factors associated with longer LOS were older age, prior atrial fibrillation, and greater patient urgency. Patient factors associated with shorter LOS were lower NYHA class, higher ejection fraction and higher mean aortic valve gradients.Procedural characteristics associated with shorter LOS were conscious sedation (HRxa0=xa01.19, 95% CI 1.06–1.35, pxa0=xa00.004). Transapical access was associated with prolonged LOS (HRxa0=xa00.49, 95% CI 0.41–0.58, pxa0<xa00.001).ConclusionThis multicenter study identified potentially modifiable patient and procedural factors associated with a prolonged LOS. Future research is needed to determine if interventions focused on these factors will translate to a shorter LOS.


Open Heart | 2018

Bedside risk score for prediction of acute kidney injury after transcatheter aortic valve replacement

Nevena Zivkovic; Gabby Elbaz-Greener; Feng Qiu; Yaron Arbel; Asim N. Cheema; Danny Dvir; Paul Fefer; Ariel Finkelstein; Stephen E. Fremes; Sam Radhakrishnan; Josep Rodés-Cabau; Mony Shuvy; Harindra C. Wijeysundera

Background Acute kidney injury (AKI) is a common post-transcatheter aortic valve replacement (TAVR) complication associated with a poor prognosis. We sought to create a risk calculator using information that would be available during the work-up period. Methods Data were obtained from a multicentre TAVR registry (n=1993) with cases from 1 January 2012 to 31 December 2015. We used logistic regression to create a risk calculator to predict AKI as defined by the Valve Academic Research Consortium Guidelines. We internally validated our risk calculator using bootstrapping, and evaluated model discrimination and calibration. Results A simple risk score was derived with six variables, including New York Heart Association functional classification class 4, non-femoral access site, valve-in-valve procedure, haemoglobin, creatinine clearance and weight in kilograms. The score was able to predict the absolute risk of AKI from 1% to 72%. The model showed good discrimination with c-statistic 0.713, with good agreement between predicted and observed AKI rates across quintiles of risk. Conclusions This is the first risk calculator to assess post-TAVR risk of AKI. We found that information known pre-procedurally can be used to predict AKI. This may allow for more informed decision-making as well as identifying high-risk patients.


Canadian Journal of Cardiology | 2017

Use of Two-Dimensional Ultrasonographically Guided Access to Reduce Access-Related Complications for Transcatheter Aortic Valve Replacement

Gabby Elbaz-Greener; Nevena Zivkovic; Yaron Arbel; Sam Radhakrishnan; Stephen E. Fremes; Harindra C. Wijeysundera

BACKGROUNDnMajor vascular complications have been associated with increased mortality and morbidity in patients undergoing transcatheter aortic valve replacement (TAVR). Our objective was to compare vascular and bleeding outcomes with the routine use of 2-dimensional ultrasonography (2D-US) guided femoral artery access in percutaneous transfemoral TAVR compared with traditional anatomic landmark palpation with angiographically-guided access.nnnMETHODSnThis single-centre retrospective cohort study was conducted in Ontario, Canada. We enrolled patients from January 1, 2012-June 30, 2016. Routine 2D-US was used in all transfemoral TAVR after January 1, 2014; before this, all cases were performed with angiographic guidance alone.nnnRESULTSnThe primary outcome of interest was the composite of any access-related red blood cell transfusion or vascular/bleeding complications. Definitions were based on the Valve Academic Research Consortium (VARC-2) criteria. Fully adjusted multivariable regression models were developed to determine the impact of 2D-US. The study cohort included 387 patients, 109 (28%) of whom underwent femoral artery puncture guided by anatomic and angiographic landmarks, whereas 278 (72%) patients had 2D-US guidance. After adjusting for baseline differences in our multivariable models, we found that 2D-US-guided access was associated with an odds ratio of 0.42 (95% confidence interval, 0.25-0.70; P < 0.01) for the composite end point of access-related vascular or bleeding complications and red blood cell transfusion.nnnCONCLUSIONSnThe routine use of 2D-US in transfemoral TAVR was associated with substantial reductions in access-related vascular and bleeding complications.


Journal of the American College of Cardiology | 2012

SMALLER LEFT VENTRICLE DIAMETER AS AN INDEPENDENT RISK FACTOR OF POST TAVI IN HOSPITAL MACE

Hirotsugu Mitsuhashi; Sam Radhakrishnan; Stephen E. Fremes

Trans-catheter aortic valve implantation (TAVI) severe complications are clinically important although their etiology is unclear. The objective of this study was to identify risk factors of in hospital major adverse cardiovascular events (MACE) post TAVI.nn82 consecutive patients who underwent TAVI


Canadian Journal of Cardiology | 2017

TAVI FOR UNDER 70 AND OVER 90 YEARS OLD PATIENTS

H. Mitsuhashi; I. Komatsu; Sam Radhakrishnan; Dennis T. Ko; Stephen E. Fremes


Canadian Journal of Cardiology | 2017

BEDSIDE RISK SCORE FOR PREDICTION OF ACUTE KIDNEY INJURY POST TRANS-CATHETER AORTIC VALVE REPLACEMENT

Nevena Zivkovic; Gabby Elbaz-Greener; F. Qui; Yaron Arbel; Asim N. Cheema; Danny Dvir; Paul Fefer; Ariel Finkelstein; Stephen E. Fremes; Sam Radhakrishnan; Josep Rodés-Cabau; Mony Shuvy; Harindra C. Wijeysundera


Canadian Journal of Cardiology | 2016

TAVI FOR LEAN PATIENTS

H. Mitsuhashi; I. Komatsu; K. Abe; Dennis T. Ko; Sam Radhakrishnan; Stephen E. Fremes


Alzheimers & Dementia | 2016

COGNITIVE OUTCOMES FOLLOWING TRANSCATHETER AORTIC VALVE IMPLANTATION (TAVI)

Maisha M. Khan; Nathan Herrmann; Sam Radhakrishnan; Harindra Wijeysundera; Stephen E. Fremes; Damien Gallagher; Dov Gandell; Kathleen McCaig; Ka S. Lai; Krista L. Lanctôt


Canadian Journal of Cardiology | 2012

178 Safety and Efficacy of Valve in Valve in TAVI

H. Mitsuhashi; Rafael Wolff; Dennis T. Ko; Sam Radhakrishnan; Stephen E. Fremes

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Stephen E. Fremes

Sunnybrook Health Sciences Centre

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Harindra C. Wijeysundera

Sunnybrook Health Sciences Centre

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Nevena Zivkovic

Sunnybrook Health Sciences Centre

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Dennis T. Ko

Sunnybrook Health Sciences Centre

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Gabby Elbaz-Greener

Sunnybrook Health Sciences Centre

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