Favorable changes in cardiac geometry and function following gastric bypass surgery: 2-year follow-up in the Utah obesity study

Abstract

Objectives: The objective of this study was to test the hypothesis that gastric bypass surgery (GBS) would favorably impact cardiac remodeling and function.

Background: GBS is increasingly used to treat severe obesity, but there are limited outcome data.

Methods: We prospectively studied 423 severely obese patients undergoing GBS and a reference group of severely obese subjects that did not have surgery (n = 733).

Results: At a 2-year follow up, GBS subjects had a large reduction in body mass index compared with the reference group (-15.4 ± 7.2 kg/m(2) vs. -0.03 ± 4.0 kg/m(2); p < 0.0001), as well as significant reductions in waist circumference, systolic blood pressure, heart rate, triglycerides, low-density lipoprotein cholesterol, and insulin resistance. High-density lipoprotein cholesterol increased. The GBS group had reductions in left ventricular (LV) mass index and right ventricular (RV) cavity area. Left atrial volume did not change in GBS but increased in reference subjects. In conjunction with reduced chamber sizes, GBS subjects also had increased LV midwall fractional shortening and RV fractional area change. In multivariable analysis, age, change in body mass index, severity of nocturnal hypoxemia, E/E', and sex were independently associated with LV mass index, whereas surgical status, change in waist circumference, and change in insulin resistance were not.

Conclusions: Marked weight loss in patients undergoing GBS was associated with reverse cardiac remodeling and improved LV and RV function. These data support the use of bariatric surgery to prevent cardiovascular complications in severe obesity.

Figure 1. Flow Chart Showing the Numbers of Subjects With Echocardiographic Examinations at Each Stage of the Study

Figure 2. Changes iln Cardiac Geometry and Function Between Visit 1 (Baseline) and Visit 2 (~2-Year Follow-Up) in the GBS and Nonsurgical Control Groups

(A) Change in absolute left ventricular (LV) mass. (B) Change in left atrial (LA) volume. (C) Change in midwall fractional shortening (MWFS); other abbreviations as in Figure 1.