Improvement in Dilated Cardiomyopathy After Bariatric Surgery

Improvement in Dilated Cardiomyopathy After Bariatric Surgery

Journal of Cardiac Failure Vol. 14 No. 3 2008 Clinical Investigations Improvement in Dilated Cardiomyopathy After Bariatric Surgery BRYAN RISTOW, MD...

456KB Sizes 84 Downloads 128 Views

Journal of Cardiac Failure Vol. 14 No. 3 2008

Clinical Investigations

Improvement in Dilated Cardiomyopathy After Bariatric Surgery BRYAN RISTOW, MD, JOHN RABKIN, MD, AND ERNEST HAEUSSLEIN, MD San Francisco, California

ABSTRACT Background: Young severely obese patients with advanced heart failure may not be suitable candidates for cardiac transplantation because of surgical morbidity and availability of adequately sized donor hearts. Methods and Results: We report 2 patients with severe systolic dysfunction and Class IV heart failure despite maximal medical therapy who were considered for cardiac transplantation. Because of their severe obesity, transplantation was not considered an optimal therapy, and both were referred for bariatric surgery. The individuals had nonischemic cardiomyopathy. Both underwent laparoscopic vertical gastrectomy, minimizing surgical risk while providing definitive reduction in gastric volume. They experienced substantial weight loss and resolution of dyspnea. Inotrope infusion was discontinued in 1 dobutaminedependent individual. They achieved weight reduction of 46 to 52 kg after the surgery. End-systolic volume index improved from 64 to 49 mL/m2 and from 66 to 39 mL/m2. Left ventricular ejection fraction improved from 20% to 45% and from 25% to 39%. They remain symptom-free and are no longer listed for transplant at 2 years’ follow-up. Conclusions: Bariatric surgery may lead to improvement in left ventricular systolic dysfunction in young morbidly obese individuals with nonischemic cardiomyopathy. Potential explanations for the improvement in left ventricular function include reduced direct toxic effects of adiposity on cardiomyocytes and improved hemodynamics after weight loss. The potential for bariatric surgery to provide an alternative to heart transplantation in extreme obesity merits further study. (J Cardiac Fail 2008;14:198e202) Key Words: Obesity, heart failure, cardiac transplantation, gastrectomy.

Obesity increases risk of mortality,1 particularly among those younger than age 75.2 The increased risk of mortality may be multifactorial, mediated by coronary artery disease, diabetes mellitus, hypertension,3e5 hyperlipidemia,6 or direct cardiotoxic effect of adiposity on the heart.7 Obesity is associated with increased risk of left ventricular (LV) hypertrophy,8 and each unit increase in body mass index (BMI) has been associated with a 2-fold increased risk of heart failure.9 Modest weight loss has been shown to increase lifespan in diabetics10 and to reduce mortality in overweight women.11 The benefit of weight loss in patients with cardiomyopathy is less well established. Observation of 1929 patients with LV systolic dysfunction found weight loss to be

associated with cardiac cachexia and increased risk of mortality.12 However, improvement in cardiac function has been reported after bariatric surgery for extreme obesity.13 We report bariatric surgery leading to improved cardiac function in 2 individuals with end-stage heart failure under consideration for cardiac transplantation. Echocardiographic measurements were made by a cardiologist blinded to case histories. Case 1 A 35-year-old male with severe obesity (weight 148 kg, BMI 43 kg/m2) was experiencing increasing fatigue and dyspnea on exertion. He had a history of dilated cardiomyopathy, severely reduced LV ejection fraction, obstructive sleep apnea, and pulmonary hypertension. Examination showed blood pressure 115/70 mm Hg, a regular pulse of 90, jugular venous distention, and diminished intensity heart sounds without murmurs, rubs, or gallops. Lung fields were clear. He had repeated hospital admissions for heart failure decompensation, and he was referred for cardiac transplantation.

From the California Pacific Medical Center, San Francisco, CA. Manuscript received July 21, 2007; revised manuscript received December 9, 2007; revised manuscript accepted December 18, 2007. Reprint requests: Dr. Bryan Ristow, California Pacific Medical Center, Department of Cardiology, Kanbar Cardiac Center, 2333 Buchanan Street, Room 1-109, San Francisco, CA 94115. 1071-9164/$ - see front matter Ó 2008 Elsevier Inc. All rights reserved. doi:10.1016/j.cardfail.2007.12.006

198

Improvement in Dilated Cardiomyopathy After Bariatric Surgery

The patient was evaluated by a heart failure specialist (EH), and his medications were increased to a maximum tolerated regimen of carvedilol 25 mg twice daily, captopril 37.5 mg 3 times daily, and Aldactone 25 mg daily. He was also receiving furosemide 80 mg daily. A sleep study showed multiple episodes of apnea, and treatment with bilevel positive airway pressure was begun. He attempted weight loss, but was unable to lose more than 7 kg with diet alone. His medication regimen was stable for 4 months, but his symptoms of fatigue and dyspnea worsened, and further diagnostic tests were performed. Right heart catheterization in May 2005 showed right atrial pressure 18 mm Hg, right ventricular pressure 60/ 17 mm Hg, pulmonary artery pressure 57/30 mm Hg, and pulmonary capillary wedge pressure 31 mm Hg. Cardiac index determined by the Fick method was 1.6 Lminm2, and by thermodilution was 1.8 Lminm2. There was no angiographic evidence of coronary artery disease. Echocardiography demonstrated a severely dilated left ventricle with global hypokinesis. The right ventricle was mildly dilated with moderate to severe hypokinesis. There was moderate pulmonary hypertension, and no hemodynamically significant valvular disease. LV volumes and ejection fraction are shown in Table 1. The patient was unable to lose further weight. His degree of obesity excluded availability for cardiac transplantation, and he therefore was considered for bariatric surgery. He underwent laparoscopic vertical gastrectomy in August 2005. At 5 months, he had lost 46 kg and noted significant improvement in his level of dyspnea. He had no further hospital admissions for heart failure. He was taken off bilevel positive airway pressure 3 months after surgery, and the

Table 1. Weight and Echocardiographic Parameters in 2 Individuals with Severe Cardiomyopathy who Underwent Bariatric Surgery 2 Years After Bariatric Baseline Surgery

Change

35-Year-Old Male Weight (kg) Body mass index (kg/m2) Body surface area (m2) Left atrial volume (mL) End-systolic volume (mL) End-systolic volume index (mL/m2) End-diastolic volume (mL) End-diastolic volume index (mL/m2) Ejection fraction

148 43 2.7 137 173 65 215 81 20%

79 23 2.0 57 99 49 180 89 45%

69 20 0.7 80 74 16 35 8 25

( 46%) ( 46%) ( 26%) ( 58%) ( 43%) ( 25%) ( 16%) (10%) (125%)

36-Year-Old Female Weight (kg) Body mass index (kg/m2) Body surface area (m2) End-systolic volume (mL) End-systolic volume index (mL/m2) End-diastolic volume (mL) End-diastolic volume index (mL/m2) Ejection fraction

129 56 2.1 141 66 188 88 25%

83 37 1.8 71 39 117 65 39%

46 19 0.3 70 27 71 23 14

( 36%) ( 36%) ( 14%) ( 50%) ( 41%) ( 38%) ( 26%) (56%)



Ristow et al

199

loop diuretic was discontinued. The patient was taken off the transplant list. Figure 1 shows comparisons of M-mode tracings in the parasternal long axis of the left ventricle before and after bariatric surgery. By January 2007, his weight was reduced to 79 kg. Table 1 shows weight loss and LV volumes. Figure 1 shows M-mode tracings from the parasternal long axis before and after surgery. Case 2 A 36-year-old female with morbid obesity, decompensated heart failure, and pulmonary hypertension was admitted November 2002 for worsening symptoms. She was experiencing dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, and lower extremity edema. She had been undergoing treatment with carvedilol 12.5 twice daily, captopril 50 mg 3 times daily, and digoxin 0.125 mg daily. Her weight was 129 kg, with a BMI of 56 kg/m2. On examination, her blood pressure was 90/60 mm Hg and there was a regular pulse of 90. Heart sounds were distant with a faint systolic murmur at the base and no rubs or gallops. Lungs were clear, and there was moderate lower extremity edema. Echocardiogram showed LV measurements as shown in Table 1. The right atrium and ventricle were moderately dilated with severely reduced right ventricular systolic function. There was no hemodynamically significant valvular disease. Right heart catheterization showed a right atrial pressure of 27 mm Hg, right ventricular pressure 71/17 mm Hg, pulmonary artery pressure of 74/30 mm Hg, and a pulmonary capillary wedge pressure 30 mm Hg. Cardiac index by Fick equation and thermodilution was 1.6 Lminm2, and there was no evidence of coronary artery disease. She was admitted to the coronary care unit and received a dobutamine infusion and intravenous diuresis with resulting improvement in weight to 123 kg (BMI 53). After multiple failed attempts at weaning dobutamine, she was discharged with a continuous home dobutamine infusion. She was listed for cardiac transplantation, but availability was not practical because of obesity, and she was referred for bariatric surgery. She was underwent laparoscopic vertical gastrectomy in April 2003. Over the next several months, the patient had symptomatic improvement in heart failure symptoms, and she was weaned off dobutamine by September 2003. She lost 63 kg with a resulting weight of 83 kg and BMI of 37 kg/ m2. Figure 2 shows a comparison of M-mode tracings from the parasternal view from an echocardiogram taken before and after bariatric surgery. Her echocardiogram results from June 2004 are shown in Table 1. The patient was taken off the transplant list. Discussion We report 2 cases of improvement in left ventricular systolic function and heart failure symptoms after bariatric surgery for severe obesity. Left ventricular ejection fraction

200 Journal of Cardiac Failure Vol. 14 No. 3 April 2008

Fig. 1. M-mode images from the 35-year-old male through the parasternal long axis show diminished thickening and excursion of the septal and inferolateral walls of the left ventricle before surgery (left) with improvement after weight loss (right).

improved from 20% to 45% and from 25% to 39%. At least 2 previous reports document improvement in cardiac function in morbidly obese individuals after a 146-kg weight loss by diet14 or a 68-kg weight loss with bariatric surgery.13 The current study provides echocardiographic measurements for LV volumes in 2 additional individuals. Limited data on the safety of bariatric surgery in the setting of congestive heart failure have been reported; the average length of stay was 3.3 days among 32 patients with history of congestive heart failure, compared with 3.0 days among 661 individuals without heart failure. All 32 patients survived to hospital discharge, but one 49-year-old male with severely reduced systolic function and atrial fibrillation died after readmission to the hospital with bleeding complications related to warfarin.15 Comorbidities increase the early postoperative risk of bariatric surgery. BMI, sleep apnea, asthma, metabolic syndrome, or coronary artery disease have been shown to increase the odds of prolonged hospital stay among 311

individuals.16 An analysis of 2075 patients identified male gender, BMI $50 kg/m2, hypertension, risk features for pulmonary embolism, and age $45 as risk factors for mortality.17 These risk factors were validated among 4431 patients; overall mortality was 0.7%, if 0e1 risk factor was present 0.2%, if 2e3 risk factors were present 1.1%, and if 4e5 risk factors were present 2.4%.18 Intuitively, patients with Class III or IV heart failure and severely reduced systolic function have even higher risk of mortality, and the use of a surgical approach to minimize complications merits consideration. Surgical techniques for reducing obesity can be divided into restrictive, malabsorptive, or combination procedures. Purely restrictive procedures include the laparoscopic gastric band and the vertical sleeve gastrectomy. Malabsorptive procedures include the jejunoileal bypass and the biliopancreatic diversion. Combination procedures include the duodenal switch with vertical gastrectomy and the Roux-en-Y gastric bypass that is primarily a restrictive

Fig. 2. M-mode images from the 36-year-old female through the parasternal long axis before (left) and after (right) bariatric surgery.

Improvement in Dilated Cardiomyopathy After Bariatric Surgery

procedure with a very limited component of malabsorption. The advantage of malabsorptive procedures is the potential for profound and sustained weight loss, but this effect must be counterbalanced against the potential for nutritional deficiency and greater complexity of the procedure. Cardiomyopathy related to selenium deficiency has been reported after biliopancreatic diversion.19 The advantages of laparoscopic vertical gastrectomy in our patients included: short operative time, no requirement for an anastomosis with therefore minimal risk of leak, and effective short-term weight loss. Banded gastroplasty has been shown to have similar success at achieving O50% excess weight loss when compared with Roux-en-Y bypass, though the latter group achieved greater mean weight loss.20 Laparoscopic vertical gastrectomy may provide the most benefit while minimizing surgical risk among individuals with dilated cardiomyopathy. Although comorbid conditions increase the risk of morbidity and mortality associated with the bariatric procedure, overall long-term mortality after bariatric surgery is significantly reduced. Bariatric surgery has been reported to improve weight loss, diabetes, and hypertriglyceridemia.21 Bariatric surgery has also been reported to be associated with an 11% decrease in left ventricular mass.22 Analyses of more than 4000 obese individuals showed decreased mortality after surgery as expressed by a hazard ratio 0.76 (P 5 .04); a study of nearly 10,000 individuals showed mortality reduction by a hazard ratio of 0.60 (P ! .001).23,24 Bariatric surgery reduces the impact of diabetes, hyperlipidemia, hypertension, and death from myocardial infarction. We report 2 young severely obese individuals with nonischemic cardiomyopathy benefiting from weight reduction. Body weight among the general population is associated with a U-shaped curve in respect to mortality. Both lowest and highest quintiles of BMI have been associated with worse survival in population-based studies.25 In middle-age individuals (mean age 61) with chronic heart failure, those in the fourth quintile (mean BMI 29.2) have been shown to have better survival than those at lower weight.26 In mildly overweight middle-age or elderly individuals, weight loss may not be beneficial in chronic heart failure. We believe that 2 characteristics separate the individuals described in our report from the majority of patients with chronic heart failure: younger age and extreme degree of obesity. We speculate that the detrimental effects of obesity on cardiac function become more pronounced with increasing body weight, and that these effects are partially reversible in younger individuals. The association between obesity and cardiomyopathy has been supported by epidemiologic, clinical, and pathologic studies.27 Obesity may lead to myocardial dysfunction from hemodynamic effects of increased preload and afterload caused by elevated body mass and metabolic demands of adipose tissue. Insulin resistance, renin-angiotensinaldosterone system activation, sympathetic activation, and direct fatty infiltration of myocardium may also contribute to myocardial dysfunction in obesity.28 When normal



Ristow et al

201

mechanisms of triglyceride accumulation in adipose tissue become disrupted in severe obesity, triglycerides deposit in other organs including pancreas, liver, and myocardium. Steatosis develops, and activation of neurohormonal pathways may lead to myocardial fibrosis, lipotoxicity, and apoptosis.29 The mechanism of cardiac myocyte injury may be similar to liver injury in nonalcoholic steatohepatitis, or pancreatic b-cell failure in type 2 diabetes mellitus.

Conclusion In summary, we report improvement in cardiac function after weight loss for 2 severely obese individuals with nonischemic cardiomyopathy who were considered for cardiac transplantation. With weight loss, end-systolic volume became smaller, and left ventricular ejection fraction improved. Laparoscopic vertical gastrectomy was performed, a procedure that in our opinion provides the best risk-benefit ratio in terms of weight loss and surgical risk. We believe that laparoscopic vertical gastrectomy may be an alternative to cardiac transplantation in severely obese young individuals with nonischemic cardiomyopathy. Acknowledgment We would like to thank Dr. Xiushui Ren for his assistance in making echocardiographic measurements and to Dr. Ren and Dr. Nelson B. Schiller for their comments on the manuscript.

References 1. Lopez AD, Mathers CD, Ezzati M, Jamison DT, Murray CJ. Global and regional burden of disease and risk factors, 2001: systemic analysis of population health data. Lancet 2006;370:109e10. 2. Stevens J, Cai J, Pamuk ER, Williamson DF, Thun MJ, Wood JL. The effect of age on body mass index and mortality. N Engl J Med 1998; 338:1e7. 3. Wolf HK, Tuomilehto J, Kuulasmaa K, Domarkiene S, Cepaitis Z, Molarius A, et al. Blood pressure levels in the 41 populations of the WHO MONICA project. J Hum Hypertens 1997;11:733e42. 4. Cassano PA, Segal MR, Vokonas PS, Weiss ST. Body fat distribution, blood pressure, and hypertension: a prospective cohort study of men in the normative aging study. Ann Epidemiol 1990;1:33e48. 5. Kastarinen MJ, Nissinen AM, Vartiainen EA. Blood pressure levels and obesity trends in hypertensive and normotensive Finnish population from 1982 to 1997. J Hypertens 2000;18:255e62. 6. Haslam DW, James WP. Obesity. Lancet 2005;366:1197e209. 7. McGavock JM, Victor RG, Unger RH, Szczepaniak LS. Adiposity of the heart, revisited. Ann Int Med 2006;144:517e24. 8. Kenchaiah S, Gaziano JM, Vasan RS. Impact of obesity on the risk of heart failure and survival after the onset of heart failure. Med Clin North Am 2004;88:1273e94. 9. Kenchaiah S, Evans JC, Levy D, Wilson PW, Benjamin EJ, Larson MG, et al. Obesity and the risk of heart failure. N Eng J Med 2002;347:305e13. 10. Lean ME, Powrie JK, Anderson AS, Garthwaite PH. Obesity, weight loss, and prognosis in type 2 diabetes. Diabetes Med 1990;7:228e33.

202 Journal of Cardiac Failure Vol. 14 No. 3 April 2008 11. Williamson DF, Parnuk E, Thues M, Flanders D, Byers T, Heath C. Modest intentional weight loss increases life expectancy in overweight women. Am J Epidemiol 1995;141:1128e41. 12. Anker SD, Negassa A, Coats AJ, Afzal R, Poole-Wilson PA, Cohn JN, et al. Prognostic importance of weight loss in chronic heart failure and the effect of treatment with angiotensin-converting-enzyme inhibitors: an observational study. Lancet 2003;361:1077e83. 13. Iyengar S, Leier CV. Rescue bariatric surgery for obesity-induced cardiomyopathy. Am J Med 2006;119:e5e6. 14. Zuber M, Kaeslin T, Studer T, Erne P. Weight loss of 146 kg with diet and reversal of severe congestive heart failure in a young morbidly obese patient. Am J Card 1999;84:955e6. 15. Alsabrook GD, Goodman HR, Alexander JW. Gastric bypass for morbidly obese patients with established cardiac disease. Obes Surg 2006;16:1272e7. 16. Ballantyne GH, Svahn J, Capella RF, et al. Predictors of prolonged hospital stay following open and laparoscopic gastric bypass for morbid obesity: body mass index, length of surgery, sleep apnea, asthma, and the metabolic syndrome. Obes Surg 2004;14:1042e50. 17. Demaria EJ, Portenier D, Wolfe L. Obesity surgery mortality risk score: proposal for a clinically useful score to predict mortality risk in patients undergoing gastric bypass. Surg Obes Relat Dis 2007;3:34e40. 18. DeMaria EJ, Murr M, Byrne TK, et al. Validation of the obesity surgery mortality risk score in a multicenter study proves it stratifies mortality risk in patients undergoing gastric bypass for morbid obesity. Ann Surg 2007;246:578e84. 19. Boldery R, Fielding G, Rafter T, Pascoe AL, Scalia GM. Nutritional deficiency of selenium secondary to weight loss (bariatric) surgery

20.

21.

22.

23.

24. 25.

26.

27. 28. 29.

associated with life-threatening cardiomyopathy. Heart Lung Circ 2007;16:123e6. Kalfarentzos F, Skroubis G, Kehagias I, Mead N, Vagenas K. A prospective comparison of vertical banded gastroplasty and Roux-en-Y gastric bypass in a non-superobese population. Obes Surg 2006;16:151e8. Sjostrom L, Lindroos AK, Peltonen M, Torgerson J, Bouchard C, Carlsson B, et al. Lifestyle, diabetes, and cardiovascular risk factors 10 years after bariatric surgery. N Engl J Med 2004;351:2683e93. Gahtan V, Goode SE, Kurto HZ, Schocken DD, Powers P, Rosemurgy AS. Body composition and source of weight loss after bariatric surgery. Obes Surg 1997;7:184e8. Sjoestroem L, Narbro K, Sjoestroem D, et al. Effects of bariatric surgery on mortality in Swedish obese subjects. N Engl J Med 2007;357:741e52. Adams TD, Gress RE, Smith SC, et al. Long-term mortality after gastric bypass surgery. N Engl J Med 2007;357:753e61. Dolan CM, Kraemer H, Browner W, Ensrud K, Kelsy J. Associations between body composition, anthropometry, and mortality in women aged 65 years and older. Am J Public Health 2007;97:913e8. Davos CH, Doehner W, Rauchhaus M, et al. Body mass and survival in patients with chronic heart failure without cachexia: the importance of obesity. J Card Fail 2003;9:29e35. Wong C, Marwick TH. Obesity cardiomyopathy: pathogenesis and pathophysiology. Nat Clin Pract Cardiovasc Med 2007;4:436e43. Wong C, Marwick T. Obesity cardiomyopathy: diagnosis and therapeutic implications. Nat Clin Practice 2007;4:480e90. McGavock JM, Victor RG, Under RH, Szczepaniak LS. Adiposity of the heart, revisited. Ann Int Med 2006;144:517e24.