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Body Mass Index Does Not Predict Mortality After Left Ventricular Assist Device Implantation
Journal of Cardiac Failure Vol.
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No.
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2015
Research Letter Body Mass Index Does Not Predict Mortality After Left Ventricular Assist Device Implantation
of participants should be done to confirm these findings and recommendations. A major limitation of our review is the small number of studies that met our inclusion criteria. Another limitation is that there was unexplained heterogeneity between studies, which is expected in meta-analyses of observational studies. Potential sources of heterogeneity are differences in cardiac function and comorbidities. In conclusion, this is the 1st systematic review and metaanalysis of published observational studies to evaluate the association between abnormal body mass index and mortality risk after LVAD implantation in heart failure patients. These results support the conclusion that underweight and obesity are not statistically significant risk factors for mortality after LVAD implantation.
To the Editor: We read the article written by Mohamedali et al1 with interest. The authors retrospectively reviewed and compared risk of mortality in patients who underwent left ventricular assist device (LVAD) placement between obese and nonobese groups. They used Kaplan-Meier survival analysis and found that there was no difference in overall survival after 3 years after LVAD between the 2 groups. The result was interesting and would most likely affect LVAD implantation candidacy. However, pooled association between obesity and mortality in patients with LVAD from similar studies is unknown. We performed a systematic review and meta-analysis of all published studies evaluating body mass index (BMI) and mortality risk in heart failure patients who had LVADs implanted. We excluded reviews, case reports, letters, commentaries, abstracts, and unpublished studies. We performed a systematic search in the Cochrane Central Register of Controlled Trials, Pubmed/medline, and Embase databases through June 2015. We extracted data concerning study design, participant characteristics, comorbidities, and odds ratio (OR) and confidence interval (CI) of post-LVAD mortality in the multivariable model. We estimated the pooled OR of mortality by means of a random effects model in Comprehensive Meta-Analysis 3.0 software. We compared mortality of patients with obesity (BMI $30 kg/m2) versus normal BMI, and underweight (BMI #18.5 kg/m2) versus normal BMI. The heterogeneity of effect size estimates across these studies was quantified with the use of the I2 statistic and Q statistic. A total of 7 articles underwent full-length review. Data from 4 observational studies2e5 involving 1,772 participants were extracted and included in the meta-analysis. Pooled OR of underweight and mortality was 2.48 (95% CI 0.89e6.95; P 5 .08; I2 5 73%; Pheterogeneity 5 .02). Pooled OR of obesity and mortality was 1.59 (95% CI 0.51e5.01; P 5 .43; I2 5 74%; Pheterogeneity 5 .02; Fig. 1). Although earlier studies found a significant association between low or high BMI and mortality risk, we did not observe such association in the pooled analysis. Many have recommended not to exclude cardiac patients with extreme BMI from LVAD implantation. Our finding supports this recommendation. However, we advise that clinicians must remain aware of the specific risks in this vulnerable group of patients. Larger prospective studies involving a variety
Disclosures None. Sikarin Upala, MD, MS Anawin Sanguankeo, MD Department of Internal Medicine Bassett Medical Center and Columbia University College of Physicians and Surgeons Cooperstown New York, USA Department of Preventive and Social Medicine Faculty of Medicine Siriraj Hospital Mahidol University Bangkok, Thailand References 1. Mohamedali B, Yost G, Bhat G. Obesity as a risk factor for consideration for left ventricular assist devices. J Card Fail 2015. http: //dx.doi.org/10.1016/j.cardfail.2015.06.006. 2. Mano A, Fujita K, Uenomachi K, Kazama K, Katabuchi M, Wada K, et al. Body mass index is a useful predictor of prognosis after left ventricular assist system implantation. J Heart Lung Transplant 2009;28:428e33. 3. Musci M, Loforte A, Potapov EV, Krabatsch T, Weng Y, Pasic M, et al. Body mass index and outcome after ventricular assist device placement. Ann Thorac Surg 2008;86:1236e42. 4. Butler J, Howser R, Portner PM, Pierson RN 3rd. Body mass index and outcomes after left ventricular assist device placement. Ann Thorac Surg 2005;79:66e73. 5. Brewer RJ, Lanfear DE, Sai-Sudhakar CB, Sundareswaran KS, Ravi Y, Farrar DJ, et al. Extremes of body mass index do not impact mid-term survival after continuous-flow left ventricular assist device implantation. J Heart Lung Transplant 2012;31:167e72. http://dx.doi.org/10.1016/j.cardfail.2015.07.016
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2 Journal of Cardiac Failure Vol.
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No.
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2015
Fig. 1. Forest plots of odds ratio (OR) for mortality comparing (A) underweight versus normal body mass index (BMI) and (B) obese versus normal BMI. CI, confidence interval.
-
No.
-
2015
Research Letter Body Mass Index Does Not Predict Mortality After Left Ventricular Assist Device Implantation
of participants should be done to confirm these findings and recommendations. A major limitation of our review is the small number of studies that met our inclusion criteria. Another limitation is that there was unexplained heterogeneity between studies, which is expected in meta-analyses of observational studies. Potential sources of heterogeneity are differences in cardiac function and comorbidities. In conclusion, this is the 1st systematic review and metaanalysis of published observational studies to evaluate the association between abnormal body mass index and mortality risk after LVAD implantation in heart failure patients. These results support the conclusion that underweight and obesity are not statistically significant risk factors for mortality after LVAD implantation.
To the Editor: We read the article written by Mohamedali et al1 with interest. The authors retrospectively reviewed and compared risk of mortality in patients who underwent left ventricular assist device (LVAD) placement between obese and nonobese groups. They used Kaplan-Meier survival analysis and found that there was no difference in overall survival after 3 years after LVAD between the 2 groups. The result was interesting and would most likely affect LVAD implantation candidacy. However, pooled association between obesity and mortality in patients with LVAD from similar studies is unknown. We performed a systematic review and meta-analysis of all published studies evaluating body mass index (BMI) and mortality risk in heart failure patients who had LVADs implanted. We excluded reviews, case reports, letters, commentaries, abstracts, and unpublished studies. We performed a systematic search in the Cochrane Central Register of Controlled Trials, Pubmed/medline, and Embase databases through June 2015. We extracted data concerning study design, participant characteristics, comorbidities, and odds ratio (OR) and confidence interval (CI) of post-LVAD mortality in the multivariable model. We estimated the pooled OR of mortality by means of a random effects model in Comprehensive Meta-Analysis 3.0 software. We compared mortality of patients with obesity (BMI $30 kg/m2) versus normal BMI, and underweight (BMI #18.5 kg/m2) versus normal BMI. The heterogeneity of effect size estimates across these studies was quantified with the use of the I2 statistic and Q statistic. A total of 7 articles underwent full-length review. Data from 4 observational studies2e5 involving 1,772 participants were extracted and included in the meta-analysis. Pooled OR of underweight and mortality was 2.48 (95% CI 0.89e6.95; P 5 .08; I2 5 73%; Pheterogeneity 5 .02). Pooled OR of obesity and mortality was 1.59 (95% CI 0.51e5.01; P 5 .43; I2 5 74%; Pheterogeneity 5 .02; Fig. 1). Although earlier studies found a significant association between low or high BMI and mortality risk, we did not observe such association in the pooled analysis. Many have recommended not to exclude cardiac patients with extreme BMI from LVAD implantation. Our finding supports this recommendation. However, we advise that clinicians must remain aware of the specific risks in this vulnerable group of patients. Larger prospective studies involving a variety
Disclosures None. Sikarin Upala, MD, MS Anawin Sanguankeo, MD Department of Internal Medicine Bassett Medical Center and Columbia University College of Physicians and Surgeons Cooperstown New York, USA Department of Preventive and Social Medicine Faculty of Medicine Siriraj Hospital Mahidol University Bangkok, Thailand References 1. Mohamedali B, Yost G, Bhat G. Obesity as a risk factor for consideration for left ventricular assist devices. J Card Fail 2015. http: //dx.doi.org/10.1016/j.cardfail.2015.06.006. 2. Mano A, Fujita K, Uenomachi K, Kazama K, Katabuchi M, Wada K, et al. Body mass index is a useful predictor of prognosis after left ventricular assist system implantation. J Heart Lung Transplant 2009;28:428e33. 3. Musci M, Loforte A, Potapov EV, Krabatsch T, Weng Y, Pasic M, et al. Body mass index and outcome after ventricular assist device placement. Ann Thorac Surg 2008;86:1236e42. 4. Butler J, Howser R, Portner PM, Pierson RN 3rd. Body mass index and outcomes after left ventricular assist device placement. Ann Thorac Surg 2005;79:66e73. 5. Brewer RJ, Lanfear DE, Sai-Sudhakar CB, Sundareswaran KS, Ravi Y, Farrar DJ, et al. Extremes of body mass index do not impact mid-term survival after continuous-flow left ventricular assist device implantation. J Heart Lung Transplant 2012;31:167e72. http://dx.doi.org/10.1016/j.cardfail.2015.07.016
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2 Journal of Cardiac Failure Vol.
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No.
- -
2015
Fig. 1. Forest plots of odds ratio (OR) for mortality comparing (A) underweight versus normal body mass index (BMI) and (B) obese versus normal BMI. CI, confidence interval.