Endocrine Abstracts

Introduction: Morbid obesity has serious associated co morbidities and is an independent risk factor for ischaemic heart disease. Obesity together with low functional status and exercise tolerance makes pre-operative cardiac assessment difficult and patients with few cardiac risk factors are often referred for cardiac assessment. This can not only be burdensome to services and prolongs waiting times for surgery but can also cause patient anxiety and poor compliance.

Background: The revised cardiac risk index (RCRI) is a validated risk stratification tool for predicting the risk of major cardiac events in the non-cardiac surgical setting. Multiple factors like type of surgery, history of ischaemic heart disease, history of congestive heart failure, history of cerebrovascular disease,preoperative treatment with insulin and preoperative serum creatinine (>2 mg/dl) stratify individuals into four categories (I, II, III and IV), the risk of cardiac events increases with each category (0.4, 0.9. 6.6, and 11% respectively).

Aim: The aim of this study is to assess whether the number of referrals to cardiology could be reduced by applying RCRI, yet still capture all of the pre-operative cardiac therapeutic interventions. We also studied the impact of cardiology referral on waiting times, development of cardiac complication whilst awaiting surgery and associated symptomatology of patients requiring cardiac intervention.

Methods: Between 2005 and 2014, a cohort of 1040 patients that had been evaluated for weight loss surgery was identified. Retrospective analysis of the clinical records was undertaken. Referrals to cardiology at this time were based on clinical judgement. Data collected included: RCRI, referral to cardiology, symptomatology, cardiac investigations and interventions, waiting time, morbidity and mortality.

Results: Out of 1040 patients, 868 patients were not referred to cardiology and did not require any cardiac intervention (0.0%). 172 (16%) were referred to cardiology, nine of the 172 patients (5%) required cardiac intervention; of which, six patients (20%) belonged to RCRI category III and IV (n=30) compared to three patients (2%) in category I and II (n=142), making patients in category III and IV significantly more likely to receive cardiac intervention (P<0.01). Waiting time for surgery was significantly higher in cardiology referral group (Median: 240 days) compared to non-cardiology group (Median: 0 days, P<0.01). Four patients (2%) in cardiology referral group developed myocardial Infarction whilst waiting for review (including 1 death=0.5%), which was significantly higher than those not referred to cardiology (n=0, P<0.01). Of all the patients requiring cardiac intervention (n=9), chest pain (alone or in combination with previous cardiac history or SOB) was the strongest associated symptom requiring cardiac intervention (n=8, P<0.01). This together with RCRI III and IV consisted of positive predictive value of 66.66% in this studied population.

Conclusions: Cardiology referrals significantly increase waiting time. Cardiac interventions are more likely in patients with RCRI III and IV. Application of RCRI together with symptom of chest pain can make a good risk stratification tool for cardiac assessment in bariatric patients. Limiting cardiology referrals predominantly to this group would substantially reduce waiting time, cardiac referrals and development of complications as a result.