Kalpa De Silva1, Matthew Lumley1, Balrik Kailey1, Jordi Alastruey2, Antoine Guilcher3, Kaleab N Asrress1, Sven Plein4, Michael Marber1, Simon Redwood1, Divaka Perera5. 1. King's College London British Heart Foundation Centre of Excellence, National Institute for Health Research Biomedical Research Centre at Guy's and St. Thomas's National Health Service Foundation Trust, Cardiovascular Division, The Rayne Institute, London, United Kingdom. 2. Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas's Hospital, London, United Kingdom. 3. Department of Clinical Pharmacology, St. Thomas's National Health Service Foundation Trust, London, United Kingdom. 4. Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas's Hospital, London, United Kingdom; Multidisciplinary Cardiovascular Research Centre, Leeds Institute of Genetics, Health and Therapeutics University of Leeds, Leeds, United Kingdom. 5. King's College London British Heart Foundation Centre of Excellence, National Institute for Health Research Biomedical Research Centre at Guy's and St. Thomas's National Health Service Foundation Trust, Cardiovascular Division, The Rayne Institute, London, United Kingdom. Electronic address: Divaka.Perera@kcl.ac.uk.
Abstract
OBJECTIVES: This study sought to identify the effect of coronary autoregulation on myocardial perfusion during intra-aortic balloon pump (IABP) therapy. BACKGROUND: IABP is the most commonly used circulatory support device, although its efficacy in certain scenarios has been questioned. The impact of alterations in microvascular function on IABP efficacy has not previously been evaluated in humans. METHODS: Thirteen patients with ischemic cardiomyopathy (left ventricular ejection fraction: 34 ± 8%) undergoing percutaneous coronary intervention were recruited. Simultaneous intracoronary pressure and Doppler-flow measurements were undertaken in the target vessel following percutaneous coronary intervention, during unassisted and IABP-assisted conditions. Coronary autoregulation was modulated by the use of intracoronary adenosine, inducing maximal hyperemia. Wave intensity analysis characterized the coronary wave energies associated with balloon counterpulsation. RESULTS: Two unique diastolic coronary waves were temporally associated with IABP device use; a forward compression wave and a forward expansion wave caused by inflation and deflation, respectively. During basal conditions, IABP therapy increased distal coronary pressure (82.4 ± 16.1 vs. 88.7 ± 17.8 mm Hg, p = 0.03), as well as microvascular resistance (2.32 ± 0.52 vs. 3.27 ± 0.41 mm Hg cm s(-1), p = 0.001), with no change in average peak velocity (30.6 ± 12.0 vs. 26.6 ± 11.3 cm s(-1), p = 0.59). When autoregulation was disabled, counterpulsation caused an increase in average peak velocity (39.4 ± 10.5 vs. 44.7 ± 17.5 cm s(-1), p = 0.002) that was linearly related with IABP-forward compression wave energy (R(2) = 0.71, p = 0.001). CONCLUSIONS: Autoregulation ameliorates the effect of IABP on coronary flow. However, during hyperemia, IABP augments myocardial perfusion, principally due to a diastolic forward compression wave caused by balloon inflation, suggesting IABP would be of greatest benefit when microcirculatory reserve is exhausted.
OBJECTIVES: This study sought to identify the effect of coronary autoregulation on myocardial perfusion during intra-aortic balloon pump (IABP) therapy. BACKGROUND: IABP is the most commonly used circulatory support device, although its efficacy in certain scenarios has been questioned. The impact of alterations in microvascular function on IABP efficacy has not previously been evaluated in humans. METHODS: Thirteen patients with ischemic cardiomyopathy (left ventricular ejection fraction: 34 ± 8%) undergoing percutaneous coronary intervention were recruited. Simultaneous intracoronary pressure and Doppler-flow measurements were undertaken in the target vessel following percutaneous coronary intervention, during unassisted and IABP-assisted conditions. Coronary autoregulation was modulated by the use of intracoronary adenosine, inducing maximal hyperemia. Wave intensity analysis characterized the coronary wave energies associated with balloon counterpulsation. RESULTS: Two unique diastolic coronary waves were temporally associated with IABP device use; a forward compression wave and a forward expansion wave caused by inflation and deflation, respectively. During basal conditions, IABP therapy increased distal coronary pressure (82.4 ± 16.1 vs. 88.7 ± 17.8 mm Hg, p = 0.03), as well as microvascular resistance (2.32 ± 0.52 vs. 3.27 ± 0.41 mm Hg cm s(-1), p = 0.001), with no change in average peak velocity (30.6 ± 12.0 vs. 26.6 ± 11.3 cm s(-1), p = 0.59). When autoregulation was disabled, counterpulsation caused an increase in average peak velocity (39.4 ± 10.5 vs. 44.7 ± 17.5 cm s(-1), p = 0.002) that was linearly related with IABP-forward compression wave energy (R(2) = 0.71, p = 0.001). CONCLUSIONS: Autoregulation ameliorates the effect of IABP on coronary flow. However, during hyperemia, IABP augments myocardial perfusion, principally due to a diastolic forward compression wave caused by balloon inflation, suggesting IABP would be of greatest benefit when microcirculatory reserve is exhausted.
Authors: Simone Rivolo; Lucas Hadjilucas; Matthew Sinclair; Pepijn van Horssen; Jeroen van den Wijngaard; Roman Wesolowski; Amedeo Chiribiri; Maria Siebes; Nicolas P Smith; Jack Lee Journal: Am J Physiol Heart Circ Physiol Date: 2016-07-08 Impact factor: 4.733
Authors: Claire E Raphael; Jennifer Keegan; Kim H Parker; Robin Simpson; Julian Collinson; Vass Vassiliou; Ricardo Wage; Peter Drivas; Stephen Strain; Robert Cooper; Ranil de Silva; Rod H Stables; Carlo Di Mario; Michael Frenneaux; Dudley J Pennell; Justin E Davies; Alun D Hughes; David Firmin; Sanjay K Prasad Journal: J Cardiovasc Magn Reson Date: 2016-12-09 Impact factor: 5.364