Wil Harrison

Evaluation of a novel sphygmomanometer, which estimates central aortic blood pressure from analysis of brachial artery suprasystolic pressure waves.

Background: Central arterial pressure is a better predictor of adverse cardiovascular outcomes than brachial blood pressure, but noninvasive measurement by applanation tonometry is technically demanding. Method: Pulsecor R6.5 is a novel device adapted from a standard sphygmomanometer which estimates the central aortic pressure from analysis of low-frequency suprasystolic waveforms at the occluded brachial artery. A physics-based model, which simulates the arterial system using elastic, thin-walled tube elements and Navier–Stokes equations, is used to calculate arterial pressure and flow propagation. To determine the reliability of the device, we compared 94 central systolic pressures estimated by Pulsecor to the simultaneous directly measured central aortic pressures at the time of coronary angiography in 37 individuals. Results: There was good correlation in central SBP between catheter measurements and Pulsecor estimates by either invasive or noninvasive calibration methods (r = 0.99, P < 0.0001 and r = 0.95, P < 0.0001, respectively). The mean difference in central systolic pressure was 2.78 (SD 3.90) mmHg and coefficient of variation was 0.03 when the invasive calibration method was used. When the noninvasive calibration method was used, the mean difference in central systolic pressure was 0.25 (SD 6.31) mmHg and coefficient of variation was 0.05. Conclusion: We concluded that Pulsecor R6.5 provides a simple and easy method to noninvasively estimate central SBP, which has highly acceptable accuracy.

Outcome following heart transplantation in New Zealand Maori.

BACKGROUND Disparities in health care access and outcomes between Maori (M) and Non-Maori (NM) New Zealanders have been reported but little is known about access to and outcomes following heart transplantation (HT). METHODS A retrospective analysis was performed of M and NM who underwent HT in New Zealand. Demographic, clinical and outcome data were collected. RESULTS Of 253 patients transplanted, 176 were European, 47 M (19%) and 30 of other ethnicities. M and NM groups were compared. Median age (both 46 years), gender (17% vs 21% female), waiting time (90 vs 76 days) and diagnosis (dilated cardiomyopathy - 62% vs 58%) were similar for both groups. M were heavier (81 vs 71 kg, p<0.0001) and more were blood group A (58% vs 39%). Five year survival was similar (79% vs 78%) but 10 year survival was significantly reduced in M (54% vs 67% p=0.02). CONCLUSION The proportion of Maori who have undergone heart transplantation in New Zealand compares favourably with their proportion in the New Zealand population. The reasons for the adverse diverging outcomes after five years require further investigation.