Results
The baseline characteristics of the ORBITA participants are previously
described1. The groups were evenly balanced and
prescribing data were available for all 200 randomised participants.
Self-reported adherence data and HPLC MS/MS urinalysis data were present
for 158 and 195 patients respectively.
Optimisation of medical
therapy
At enrolment, prior to optimisation, 82 (78%) and 75 (79%) of patients
in the PCI and placebo groups respectively were prescribed aspirin, 71
(68%) and 66 (69%) patients were prescribed a statin and 20 (19%) and
28 (29%) patients were prescribed ≥ 2 anti-anginal agents. By
pre-randomization which signifies the end of OMT (Table 2) 102 and
(97%) and 92 (97%) patients were prescribed aspirin, 100 (95%) and 91
(96%) were prescribed atorvastatin or other statin and 90 (86%) and 93
(98%) patients were prescribed ≥ 2 anti-anginal agents, in the PCI and
placebo groups respectively. Most patients were prescribed two
anti-platelet agents, in keeping with guideline-directed clinical
practice for elective PCI. The most commonly prescribed,
protocol-directed anti-anginal agents were calcium channel blockers -
prescribed for 95 (90%) patients that received PCI and 87 (92%)
patients that received placebo. Prescription of anti-anginal agents was
evenly balanced between the groups, both at pre-randomisation and at
follow-up and there was no notable change in prescribing from
pre-randomisation to follow-up within groups.
Self-reported medication
adherence
Self-reported adherence was >96% for all drugs in both
treatment groups at both stages (Table 2).
Urinary HPLC MS/MS
The proportion of expected drug detected was >90% for all
first-choice, protocol-directed medicines at both stages. Conversely,
percentage adherence below 80% was not demonstrated for any drug at
pre-randomisation and was only apparent in patients that were prescribed
an alternative statin and who underwent urinary drug detection by HPLC
MS/MS at follow-up: 11 of 14 (73%) patients in the PCI group and 2 of 3
(67%) patients in the placebo group.