Assessing the impact of Cardiac Resynchronisation Therapy upon patients with Heart Failure in a real world UK setting; can routinely obtained markers provide a novel method of predicting response?

Background: Cardiac resynchronisation therapy (CRT) reduces morbidity and mortality in patients with advanced heart failure (HF). CRT is currently offered based on symptom profile, LV EF% and QRS duration, although many more parameters are measured at pre-assessment. Response rates are inconsistent, with no single, standardised method of assessment. The objective was to provide insight into a UK tertiary centre CRT population; what type of patients “respond” and do any markers predict response?

Methods and Results: Retrospective analysis of routine CRT pre-assessment data from 113 patients over a two year period was conducted. The average patient at baseline was 71, male (79%), with a BMI of 29.5. CRT significantly improved NYHA Class, HF score, exercise tolerance and 2D echocardiographic LV measurements. Response was determined at 7.49 (±3) months using Clinical Composite Score and/ or evidence of left ventricular reverse remodeling. 69% of patients with response data available were clinical responders (CR) and 51% echocardiographic responders (ER). 57% of CRs had an ER. Non-ischaemic aetiology (OR 10, 95% CI 2.6-38.5, p<0.001) and no scar on cardiac MRI (OR 24.5, 95% CI 2.3-262.5, p=0.008) were highly predictive of ER. However, no single variable was able to predict both CR and ER.

Conclusion: Data are consistent with large multi-center trials; CRT improved symptoms, echocardiographic measures and mortality. Whilst only lower NYHA class had a prognostic survival benefit, patients with HF of non-ischaemic aetiology were more likely to be ERs after 6 months. No routine pre-assessment variables were able to predict both CR and ER.