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Instantaneous wave-free ratio (iFR) can reliably assess the physiological significance of coronary artery disease (CAD). Previous studies have demonstrated its interchangeability with other non-hyperaemic pressure ratios (NHPR), but there is no data exploring whether this association is maintained in patients with severe aortic stenosis (AS).Forty-two patients (67 lesions) with severe AS were recruited and underwent invasive pressure-wire assessment. Data were extracted to calculate iFR, resting Pd/Pa, diastolic pressure ratios (DPR and dPR), and Diastolic Hyperaemia-Free Ratio (DFR). iFR was then compared with other NHPR to determine agreement and accuracy.Mean aortic gradient and dimensionless index were 44.3 ± 11.6 mmHg and 0.23 ± 0.04, respectively. Of the 67 vessels, 57% were LAD, 15% LCx, 13% RCA and 12% other. There was strong positive correlation between iFR and all other NHPR, including Pd/Pa (r = 0.91, p0.001), DPR (r = 0.99, p0.001), dPR (r = 0.97, p0.001) and DFR (r = 0.98, p0.001). While Bald-Altman analysis demonstrated that Pd/Pa and DFR were numerically different from iFR, ROC analyses demonstrated iFR ≤0.89 was accurately identified by all NHPRs; Pd/Pa (AUC = 0.965, 95% CI [0.928-0.994]), DPR (AUC = 1.000, 95% CI [1.000-1.000]), dPR (AUC = 0.974, 95% CI [0.937-1.000]), DFR (AUC = 0.989, 95% CI [0.968-1.000]).In patients with severe AS, all the included NHPR in this analysis accurately predicted iFR0.89. These data should reassure clinicians that use of alternative NHPR to iFR is reasonable when assessing the physiological significance of CAD in patients with severe AS.

Lone night medical registrars, particularly those working at busy urban hospitals have high workloads and low job satisfaction. Handover of pending referrals from day staff can contribute to further delays in providing care with increased risks for patient safety.To evaluate the impact of a staggered roster for daytime medical registrar on the workload of night registrar.Prospective data were collected of the night medical registrar workload over a 6-month period. The first 3 months included standard shifts from 1330 to 2130 hours with two registrars. The second 3 months followed the introduction of a staggered shift for one registrar to 1530 hour-midnight, providing a 3-h overlap with the night registrar commencing at 2100 hour. Parameters recorded included the number of total admissions, pending admissions, referrals from emergency department, ward reviews and Medical Emergency Team (MET) calls/CODE Blues. Data from weekends and public holidays were not recorded.During the standard rostering period, the average number of medical admissions completed per night shift was 8.66 (n = 60, SD = 3.58). With staggered shifts, the average number was significantly reduced at 6.38 (n = 65, SD = 2.74, P = 0.000057). In addition, there was greater number of ward reviews conducted by the night registrar in the staggered roster period, potentially reflecting greater time availability and reduction in MET calls/codes.Rearranging medical registrar shifts can result in significant reduction in night medical registrar workload. It may also have other potential benefits in terms of increased capacity for ward reviews and reduced MET calls/codes.