Clinical outcomes of fractional flow reserve by computed tomographic angiography-guided diagnostic strategies vs. usual care in patients with suspected coronary artery disease: the prospective longitudinal trial of FFRct: outcome and resource impacts study
Selected in European Heart Journal by G.G. Toth
Douglas PS, Pontone G, Hlatky MA, Patel MR, Norgaard BL, Byrne RA, Curzen N, Purcell I, Gutberlet M, Rioufol G, Hink U, Schuchlenz HW, Feuchtner G, Gilard M, Andreini D, Jensen JM, Hadamitzky M, Chiswell K, Cyr D, Wilk A, Wang F, Rogers C, De Bruyne B; PLATFORM Investigators
Eur Heart J. 2015 Sep 1. pii: ehv444. [Epub ahead of print]
LinkRead the abstract
In the diagnostic workup of patients with suspected coronary artery disease, computed tomographic angiography (CTA) is a potent tool for patient selection for invasive coronary angiography (ICA). CTA-derived fractional flow reserve (FFRCT) calculation is a novel technology of which impact on diagnostic strategies is unknown.
- Physician predefined the recommended diagnostic strategy for each patient before randomization: standard non-invasive strategy (NI) versus standard invasive coronary angiography (ICA)
- Afterwards patients were randomized 1:1 for standard strategy (NI or ICA, as previously adjudicated) versus CTA/FFRCT-guided strategy.
- In the usual care cohort all the patients underwent the planned diagnostic route (NI or ICA). In CTA/FFRCT cohort all subjects underwent CTA instead of the planned non-invasive or invasive evaluation and FFRCT analyses were performed centrally if the CTA revealed ≥30% stenosis or if the patient was referred to ICA.
- The primary endpoint was the rate of ICA within 90 days showing no obstructive CAD. Major safety endpoint was a composite of major adverse cardiovascular events (MACE) at 90 days: all-cause mortality, myocardial infarction and unplanned hospitalization for chest pain leading to urgent revascularization.
- 584 patients were enrolled in the study. 204 patients were initially adjudicated to standard NI strategy, while 280 patients were initially adjudicated to standard ICA.
- In patients initially adjudicated to standard NI strategy, after randomization 100 patients underwent standard NI strategy (Usual care group), and 104 patients were examined by CTA/ FFRCT (CTA/FFRCT group). In both groups less than 20% of the patients were finally sent for ICA, without significant difference in the rate of ICA, showing no obstructive CAD [6 (6.0%) vs 13 (12.5%) respectively; p=0.96].
- In patients initially adjudicated to standard ICA, after randomization 187 patients underwent directly standard ICA (Usual care group) and 193 patients were first examined by CTA/ FFRCT (CTA/FFRCT group). While in the usual care group 100% of the patients underwent ICA, in the CTA/FFRCT group only 39.4% of the patients were finally invasively examined. Comparing the two groups, a significant difference was found in the rate of ICA, showing no obstructive CAD [137 (73.3%) vs 24 (12.4%) respectively; p<0.001].
- There were no differences in rates of revascularization in subjects allocated to CTA/FFRCT vs. usual care in either the planned non-invasive or planned invasive testing arms. (p= 0.29 and 0.58, respectively).
- No difference was found in the safety endpoints at 90 days follow-up.
- Data suggest that FFRCT is a valuable tool to facilitate the screening of patients with suspected coronary artery disease. Its use is associated with significantly lower rate of coronary angiograms, showing no obstructive coronary artery disease, which might have important impact on healthcare logistics.
- Long-term clinical outcome data still need to be investigated.