VARIATIONS BETWEEN COUNTRIES IN INVASIVE CARDIAC PROCEDURES AND OUTCOMES IN PATIENTS WITH SUSPECTED UNSTABLE ANGINA OR MYOCARDIAL-INFARCTION WITHOUT INITIAL ST ELEVATION

Background There are wide variations between countries in the use of i nvasive cardiac catheterisation and revascularisation procedures for p atients with acute ischaemic syndromes. We studied the relation betwee n rates of such procedures and rates of cardiovascular death, myocardi al infarction, stroke, refractory angina, and major bleeding in a pros pective, registry-based study in six countries with widely varying int ervention rates. Methods 7987 consecutive patients presenting with uns table angina or suspected myocardial infarction without ST-segment ele vation were recruited prospectively from 95 hospitals in six countries and followed up for 6 months. Findings The rates of all procedures we re highest in patients in Brazil and the USA, intermediate in Canada a cid Australia, and lowest in Hungary and Poland. There were no signifi cant differences in rates of cardiovascular death or myocardial infarc tion among these countries (47% overall [range 3.7-5.6] at 7 days; 11% overall [9-12] at 6 months), For the countries with the highest rates of invasive procedures (59%) versus the rest (21%) there was no diffe rence in rate of cardiovascular death or myocardial infarction (adjust ed odds ratio 0.88 at 7 days and 1.0 at 6 months). Rates of stroke wer e higher in Brazil and the USA than in the countries with lower interv ention rates (adjusted odds ratio at 7 days 3.0, p=0.012; at 6 months 1.8, p=0.004) but rates of refractory angina at 7 days (0.7, p<0.001) and readmission for unstable angina at 0.83 (10.6% vs 12.5%, p=0.05) a nd for refractory angina of 1.25 (19.3% vs 16.1%, p=0.09). Interpretat ion Higher rates of invasive and revascularisation procedures were ass ociated with lower rates of refractory angina or readmission for unsta ble angina, no apparent reducton in cardiovascular death or myocardial infarction, but with higher rates of stroke. Randomised trials should assess the relative impact of conservative and more aggressive approa ches to invasive cardiac procedures and revascularisations in patients with unstable angina.