Abstract P314: Response of the Cardiometabolic Risk Profile to Coronary Artery Bypass Surgery Followed by a 1-year Lifestyle Modification Program: A Pilot Study
Authors: Valérie Lévesque, Paul Poirier, André Marette, Patrick Mathieu, Jean-Pierre Després, Éric Larose
Journal: Circulation (2012)

Introduction: A coronary artery bypass graft (CABG) surgery induces an important physiological stress which could impact on cardiometabolic risk (CMR) variables. Furthermore, lifestyle modification programs are effective in secondary prevention. Objective: The present pilot study explored the response of CMR variables to a CABG surgery followed by a 1-year intervention targeting the improvement of lifestyle habits (nutrition/physical activity) in patients with established coronary artery disease (CAD). Methods: Anthropometric measurements, assessment of lipid profile and magnetic resonance imaging were performed before and after CABG surgery (n=32) and 1 year after the lifestyle modification program (n=26). An oral glucose tolerance test (OGTT) and a maximal treadmill test (modified Bruce) were also performed after surgery and at the end of the intervention program. Results: Six weeks after surgery, but before initiation of the lifestyle modification program, patients significantly reduced their body mass index (BMI) (Δ=−1.0 kg/m 2 , p&lt;0.0001), waist circumference (Δ=−3.4 cm, p&lt;0.0001), fat mass (Δ=−2.7 kg, p&lt;0.0001), visceral (Δ=−25.5 cm 3 , p=0.007) and total abdominal adipose tissue volumes (Δ=−27.4 cm 3 , p=0.008). They also significantly decreased their LDL-C (Δ=−0.7 mmol/L, p=0.0003) and total cholesterol (Δ=−0.7 mmol/L, p&lt;0.0001), as well as their total cholesterol/HDL-C ratio (Δ=−0.8, p=0.009). In response to the lifestyle modification program, subjects further improved their CMR profile with additional decreases in their BMI (Δ=−0.9 kg/m 2 , p=0.02) and waist circumference (Δ=−4.3 cm, p=0.002) as well as visceral (Δ=−36.2 cm 3 , p=0.03), subcutaneous (Δ=−29.1 cm 3 , p=0.005) and total abdominal adipose tissue volumes (Δ=−61.1 cm 3 , p=0.01). They also significantly reduced glucose area under the curve (Δ=−128.6 ρmol/L, p=0.0005) measured during the OGTT, TG/HDL-C ratio (Δ=−0.47, p=0.0006), triglycerides (Δ=−0.12 mmol/L, p=0.03), total cholesterol/HDL-C ratio (Δ=−0.34, p=0.003) and increased HDL-C levels (Δ=+0.2 mmol/L, p=0.0002). Cardiorespiratory fitness (CRF) was also improved significantly as reflected by an increase in VO 2 max (Δ=+4.0 mlO 2 /kg/min, p&lt;0.0001) and by a reduced heart rate assessed at a standardized workload (3.5 mph, 2% slope) (Δ=−9 bpm, p&lt;0.0001). All changes in cardiometabolic risk variables were observed despite a reduction in the use of cardiometabolic drugs in some patients. A multiple regression analysis showed that improvement in CRF largely explained (r 2 =0.61, p=0.0003) the improvement in 2-hours plasma glucose (OGTT) in response to the lifestyle modification program. Conclusion: Results of this pilot study suggest that the CMR profile of high risk patients with CAD is improved by the CABG surgery itself. In addition, a 1-year lifestyle modification program generates further cardiometabolic benefits.