Author + information
- Satpal Arri,
- Rupert Williams,
- Kaleab Asrress,
- Matthew Lumley,
- Howard Ellis,
- Tiffany Patterson,
- Muhammed Khawaja,
- Divaka Perera,
- Brian Clapp,
- Michael Marber and
- Simon Redwood
Background: Mental stress (MS) triggers myocardial ischaemia at lower cardiac workloads compared to exercise stress in the same patient. Clinical relevance is highlighted by observational studies demonstrating marked increases in cardiovascular events when large populations are exposed to acute MS for example by earthquakes and publicised national sports events. In contrast, even in patients with known coronary artery disease and exertional angina, exercise is safe and beneficial.
Methods: Simultaneous intracoronary pressure and flow velocity data were acquired in a target artery from 18 patients with significant coronary artery disease (CAD) (FFR <0.8 and or stenosis >70%) and 16 controls during MS testing (mental arithmetic, stroop test) 9 CAD patients and 9 controls also underwent supine cycle ergometer exercise stress (ES) at the time of cardiac catheterisation. Studies were performed in the morning following an overnight fast and vasoactive drugs were stopped at least 24 hours in advance. Coronary flow average peak velocity (APV), microvascular resistance (MVR) and Buckberg index (BI) were calculated. Wave intensity analysis also differentiated waves that accelerate and decelerate coronary flow.
Results: At peak MS rate pressure product (RPP), a marker of myocardial oxygen demand, increased by 4165±2266mmHg.bpm (p=0<0001). Systolic blood pressure and heart rate increased by 26.4±13.0mmHg and 13.9±10.9bpm respectively (p<0.0001). Despite this there was no increase in coronary flow observed in the CAD group, but instead a 31% paradoxical rise in MVR (p=0.003) and a fall in the BI (p<0.001), a surrogate for subendocardial ischaemia. Interestingly wave free MVR, more reflective of vascular tone and less affected by the contractile forces of the ventricle, did not increase during workload matched ES. In contrast a 35% increase in coronary flow driven by the forward compression and backward expansion waves was observed in the control group (p=0.001).
Conclusions: A paradoxical rise in MVR does occur in response to MS that is not seen with ES at similar workloads. This abnormal endothelial response correlates with the extent of atherosclerosis in the vessel.
Moderated Poster Contributions
Acute and Stable Ischemic Heart Disease Moderated Poster Theater, Poster Hall, Hall C
Friday, March 17, 2017, 11:30 a.m.-11:40 a.m.
Session Title: Post-CAD/MI: Making Tough Predictions About the Future
Abstract Category: 2. Acute and Stable Ischemic Heart Disease: Clinical
Presentation Number: 1138M-15
- 2017 American College of Cardiology Foundation