Open Access
Feature Article

The cardiac complications of obesity

Open Access
Feature Article

The cardiac complications of obesity

Elizabeth Paratz, Sonny Palmer, Justin Mariani

Figures

© LIGHTSPRING/SHUTTERSTOCK
© LIGHTSPRING/SHUTTERSTOCK
Dr Paratz is a Cardiologist at St Vincent’s Hospital and the Baker Heart & Diabetes Institute, Melbourne. Associate Professor Palmer is an Interventional and Structural Cardiologist at St Vincent’s Hospital, Melbourne. Associate Professor Mariani is an Interventional Heart Failure Specialist at The Alfred Hospital, Melbourne, Vic.

There are also increasing data suggesting that even established coronary artery disease may be attenuated or reversed by weight loss. In one observational study, patients who achieved sustained weight loss with Roux-en-Y bypass had reduced coronary calcification compared with patients with obesity, and assessment of atherosclerotic carotid plaque patterns showed a similar trend.38 In the Swedish Obese Subjects study in 2012, the risk of CV events and death was significantly reduced in patients with obesity who underwent bariatric surgery compared with obese control subjects receiving usual care (hazard ratio, 0.67).15 It is worth noting, however, that in post-hoc statistical analysis, risk reduction was not able to be definitively linked with the observed weight loss; the authors suggested a range of possible reasons, including underpowering.

How can patients with morbid obesity lose weight? 

Weight loss appears increasingly to be one of our most powerful weapons against CV disease. However, achieving and sustaining significant weight loss is not easy. It is believed that a complex interplay of genetics, epigenetics, diet, exercise and shifting cultural patterns have led to the current ‘obesity epidemic’. Despite recognition of the rewarding benefits of weight loss, it is not possible to reverse all predisposing factors (i.e. strong genetic factors, possible in utero effects) for obesity. 

Practically, it is usually not feasible for patients with morbid obesity to participate in regular exercise programs to an adequate degree to achieve weight loss. Pharmacotherapy may be effective for people with obesity when combined with lifestyle modifications and can be considered to prolong weight loss after bariatric surgery.39

Obesity surgery is hence emerging as an increasingly popular first step to weight loss in the population of morbid obesity, and is likely to become more available to Australians. Government bodies are now recognising it as a cost-effective intervention, and, as mentioned above, its ability to improve health outcomes was clearly demonstrated in the STAMPEDE trial. Accumulating evidence from prospective trials has shown that various forms of bariatric surgery may have positive impacts on CV endpoints.40 

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A suggested approach for doctors involved in the care of patients with obesity is outlined in Table 3, based on the 2013 NHMRC’s Clinical Practice Guidelines for the Management of Overweight and Obesity in Adults, Adolescents and Children in Australia.9 Within these and other international guidelines, the role of referral for consideration of bariatric surgery is increasingly being emphasised, particularly for patients with comorbidities that are identifiable as obesity-related.41 Assessment before such surgery is essential and lifetime follow up afterwards is necessary as nutritional deficiencies and other side effects must be minimised.

Conclusion

Morbid obesity is increasingly common in Australia today. GPs will see many patients with morbid obesity in their practice who have associated cardiac comorbidities. It is important that doctors and patients appreciate how powerfully morbid obesity amplifies the risks of premature CV events, and that it may in fact be an even stronger risk factor than smoking. This is especially the case for people with HFpEF, where obesity is very strongly associated.

Patients with morbid obesity are likely to have many CV comorbidities, and hence earlier cardiac events. When they experience cardiac events and interventions, they are at risk of significantly worse clinical outcomes. 

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Reversal of morbid obesity appears to be a potent intervention for reversing the burden of disease experienced by the morbidly obese. Cardiac comorbidities may be alleviated by weight loss, and medication requirement may be significantly reduced. 

Alongside counselling patients sympathetically about diet and suitable exercise, GPs will increasingly be able to expedite referrals for obesity intervention to help optimise the CV risk profile of patients with obesity.     MT

 

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COMPETING INTERESTS: None.