Introduction Refractory angina describes those patients with persistence of symptoms despite revascularisation and routine pharmacotherapy with β-blockers, calcium channel antagonists and nitrates. Ranolazine offers adjunct therapy in such cohorts, by providing anti-ischaemic effects complementary to existing agents. It is thought to be well-tolerated, without significant effects on haemodynamic parameters including heart rate and blood pressure. This prospective study aimed to establish the short-term effectiveness and safety profile of ranolazine in patients with refractory angina.

Methods Bradford Royal Infirmary has a specialised cardiology service to manage refractory angina (BRAS). From their database, 50 consecutive patients were selected for inclusion between May 2013 and February 2014. All patients were commenced on ranolazine 375 mg twice daily at initial review, and therapy was continued for 1 month. Those who required up-titration of anti-anginals or revascularisation on clinical grounds were excluded from the study. Results of 6 min walks, Canadian Cardiovascular Society (CCS) grading of angina severity and QTc interval on resting ECG was tabulated, both pre-intervention and at 1 month. Wilcoxon signed rank sum testing was applied to measure differences in outcome. Patients were surveyed to assess for tolerability and adverse events.

Results 45 patients were eligible for inclusion. 87% (39/45) were male, with a mean age of 65.2 years (SD 12.3). At 1 month, there was a median increase in 6 min walk of 30 metres (95% CI: 25 – 60; p = 0.0002). CCS grading class for angina severity reduced by 0.5 (95% CI: 0 – 0.86; p < 0.0001). Daily frequency of GTN usage decreased by 50% (4 vs. 2; p = 0.068). QTc increased by 3 ms, a non-significant difference (95% CI: 6 – 12; p = 0.395). 91% (41/45) tolerated therapy without concern. In the remainder (9%), reported side-effects included fatigue, blisters, constipation and dizziness. In all cases, this resulted in discontinuation of therapy.

Conclusions These findings suggest that ranolazine offers effective additive therapy in patients with persistent anginal symptoms who have been otherwise optimised. Despite our small sample size, results demonstrated a statistically significant improvement in performance on 6 min walk, CCS grading score and usage of GTN spray. Overall, ranolazine was well-tolerated without QTc prolongation or overt side-effects. Further studies are indicated to establish whether effects are maintained in the longer term.