Introduction The ORBITA trial of PCI versus a placebo procedure for patients with stable angina was conducted across 6 sites in the United Kingdom via home monitoring and telephone consultations. Patients underwent detailed assessment of medication adherence which allowed us to measure the efficacy of the implementation of the optimisation protocol and interpretation of the main trial endpoints. Methods Prescribing data were collected throughout the trial. Self-reported adherence was assessed, and urine samples collected at pre-randomisation and at follow-up for direct assessment of adherence using HPLC MS/MS. Results Self-reported adherence was >96% for all drugs in both treatment groups at both stages. The percentage of samples in which drug was detected at pre-randomisation and at follow-up in the PCI vs. OMT groups respectively was: clopidogrel, 96% vs. 90% and 98% vs. 94%; atorvastatin, 95% vs. 92% and 92% vs. 91%; perindopril, 95% vs. 97% and 85% vs. 100%; bisoprolol, 98% vs. 99% and 96% vs. 97%; amlodipine, 99% vs. 99% and 94% vs. 96%; nicorandil, 98% vs. 96% and 94% vs. 92%; ivabradine, 100% vs. 100% and 100% vs. 100%; and ranolazine, 100% vs. 100% and 100% vs. 100%. Conclusions Adherence levels were high throughout the study when quantified by self-reporting methods and similarly high proportions of drug were detected by urinary assay. The results indicate successful implementation of the optimisation protocol delivered by telephone, an approach that could serve as a model for treatment of chronic conditions, particularly as consultations are increasingly conducted online.

Aims: A prolonged PR interval may adversely affect ventricular filling and therefore cardiac function. AV delay can be corrected using right-ventricular-pacing (RVP) but this induces ventricular dyssynchrony, itself harmful. Therefore, in intermittent heart-block, pacing-avoidance algorithms are often implemented. We tested His-bundle pacing (HBP) as an alternative. Methods: Out-patients with a long PR interval(>200ms) and intermittent need for ventricular pacing were recruited. We measured within patient differences in high-precision haemodynamics between AV-optimized RVP, and HBP, as well as a pacing-avoidance algorithm [Managed Ventricular Pacing (MVP)]. Results We recruited 18 patients. Mean left ventricular ejection fraction was 44.3±9%. Mean intrinsic PR interval was 266±42ms and QRS duration was 123±29ms. RVP lengthened QRS duration(+54 ms, 95%CI 42 to 67ms, p<0.0001) whilst HBP delivered a shorter QRS duration than RVP(-56 ms, 95%CI -67 to -46ms, p<0.0001). HBP did not increase QRS duration(-2ms 95%CI -8 to 13ms, p=0.6). HBP improved acute systolic blood pressure by mean of 5.0 mmHg(95%CI 2.8 to 7.1mmHg, p<0.0001) compared to RVP and by 3.5 mmHg(95%CI 1.9 to 5.0mmHg, p=0.0002) compared to the pacing avoidance algorithm. There was no significant difference in haemodynamics between RVP and ventricular pacing avoidance (p=0.055). Conclusions HBP provides better acute cardiac function than pacing avoidance algorithms and RVP, in patients with prolonged PR intervals. HBP allows normalisation of prolonged AV delays (unlike pacing avoidance) and does not cause ventricular dyssynchrony (unlike RVP). Clinical trials may be justified to assess whether these acute improvements translate into longer term clinical benefits in patients with bradycardia indications for pacing.