Sharing primary percutaneous coronary intervention care: first experiences with South Limburg ST-elevation myocardial infarction network.

BACKGROUND: In the region of South Limburg, the Netherlands, a shared ST-elevation myocardial infarction (STEMI) networking system (SLIM network) was implemented. During out-of-office hours, two percutaneous coronary intervention (PCI) centres-Maastricht University Medical Centre and Zuyderland Medical Centre-are supported by the same interventional cardiologist. The aim of this study was to analyse performance indicators within this network and to compare them with contemporary European Society of Cardiology guidelines. METHODS: Key time indicators for an all-comer STEMI population were registered by the emergency medical service and the PCI centres. The time measurements showed a non-Gaussian distribution; they are presented as median with 25th and 75th percentiles. RESULTS: Between 1 February 2018 and 31 March 2019, a total of 570 STEMI patients were admitted to the participating centres. The total system delay (from emergency call to needle time) was 65 min (53-77), with a prehospital system delay of 40 min (34-47) and a door-to-needle time of 22 min (15-34). Compared with in-office hours, out-of-office hours significantly lengthened system delays (55 (47-66) vs 70 min (62-81), p < 0.001), emergency medical service transport times (29 (24-34) vs 35 min (29-40), p < 0.001) and door-to-needle times (17 (14-26) vs 26 min (18-37), p < 0.001). CONCLUSIONS: With its effective patient pathway management, the SLIM network was able to meet the quality criteria set by contemporary European revascularisation guidelines.

Instantaneous wave-free ratio and fractional flow reserve in clinical practice.

OBJECTIVES: To compare fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) measurements in an all-comer patient population with moderate coronary artery stenoses. BACKGROUND: Visual assessment of the severity of coronary artery stenoses is often discordant in moderate lesions. FFR allows reliable functional severity assessment in these cases but requires adenosine-induced hyperaemia with associated additional time, costs and side effects. The iFR is a hyperaemia-independent index. METHODS AND RESULTS: Between November 2015 and February 2017, 356 consecutive patients were included in whom 515 coronary stenoses were measured using both iFR and FFR. Mean iFR and FFR were 0.90 ± 0.09 and 0.86 ± 0.08, respectively. iFR correlated well with FFR [r = 0.75; p < 0.001]. Receiver operating characteristic analysis identified an area under the curve of 0.92. An iFR-only strategy with a treatment cut-off ≤0.89 revealed a diagnostic classification agreement with the FFR-only strategy in 420 lesions (82%) with a sensitivity of 87%, a specificity of 80%, a positive predictive value of 56% and a negative predictive value of 96%. CONCLUSIONS: Real-time iFR measurements have good negative predictive value compared to FFR, but moderate diagnostic accuracy (82%). It exposes fewer patients to adenosine, reduces procedure time and costs. Further prospective trials are needed to evaluate specific clinical settings, cut-off values and endpoints.