Jay Ritzema
Christchurch Hospital
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Featured researches published by Jay Ritzema.
Circulation | 2010
Jay Ritzema; Richard W. Troughton; Iain Melton; Ian Crozier; Robert N. Doughty; Henry Krum; Anthony Walton; Philip Adamson; Saibal Kar; Prediman K. Shah; Mark Richards; James S. Whiting; Garrie Haas; J. Thomas Heywood; Chris Frampton; William T. Abraham
Background— Previous studies suggest that management of ambulatory hemodynamics may improve outcomes in chronic heart failure. We conducted a prospective, observational, first-in-human study of a physician-directed patient self-management system targeting left atrial pressure. Methods and Results— Forty patients with reduced or preserved left ventricular ejection fraction and a history of New York Heart Association class III or IV heart failure and acute decompensation were implanted with an investigational left atrial pressure monitor, and readings were acquired twice daily. For the first 3 months, patients and clinicians were blinded as to these readings, and treatment continued per usual clinical assessment. Thereafter, left atrial pressure and individualized therapy instructions guided by these pressures were disclosed to the patient. Event-free survival was determined over a median follow-up of 25 months (range 3 to 38 months). Survival without decompensation was 61% at 3 years, and events tended to be less frequent after the first 3 months (hazard ratio 0.16 [95% confidence interval 0.04 to 0.68], P=0.012). Mean daily left atrial pressure fell from 17.6 mm Hg (95% confidence interval 15.8 to 19.4 mm Hg) in the first 3 months to 14.8 mm Hg (95% confidence interval 13.0 to 16.6 mm Hg; P=0.003) during pressure-guided therapy. The frequency of elevated readings (>25 mm Hg) was reduced by 67% (P<0.001). There were improvements in New York Heart Association class (−0.7±0.8, P<0.001) and left ventricular ejection fraction (7±10%, P<0.001). Doses of angiotensin-converting enzyme/angiotensin-receptor blockers and &bgr;-blockers were uptitrated by 37% (P<0.001) and 40% (P<0.001), respectively, whereas doses of loop diuretics fell by 27% (P=0.15). Conclusions— Physician-directed patient self-management of left atrial pressure has the potential to improve hemodynamics, symptoms, and outcomes in advanced heart failure. Clinical Trial Registration Information— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00547729.
Circulation | 2007
Jay Ritzema; Iain Melton; A. Mark Richards; Ian G. Crozier; Chris Frampton; Robert N. Doughty; James S. Whiting; Saibal Kar; Henry Krum; William T. Abraham; Richard W. Troughton
Background— We describe the first human experience with a permanently implantable, direct left atrial pressure (LAP) monitoring system in ambulatory patients with chronic heart failure. Methods and Results— Eight patients with established heart failure and at least 1 heart failure hospitalization or unplanned visit for parenteral therapy in the last year underwent device implantation under fluoroscopic guidance. All subjects received aspirin 150 mg and clopidogrel 75 mg daily. Subjects measured LAP twice daily and attended a clinic regularly for data upload and device calibration. Right heart catheterization was performed at the time of device implantation and at 12 weeks. The device was implanted in all subjects with no procedural complications. At the 12-week follow-up, 87% of device LAP measurements were within ±5 mm Hg of simultaneous pulmonary capillary wedge pressure readings over a wide range of pressures (1.6 to 71 mm Hg). Net drift corrected by calibration was −0.2±1.9 mm Hg/mo. During short-term follow-up, there were no device-related complications or systemic emboli. There were no deaths, no unplanned heart failure clinic visits, and no admissions for heart failure. Conclusions— Ambulatory monitoring of direct LAP with a new implantable device was well tolerated, feasible, and accurate at a short-term follow-up. Further follow-up and investigation are warranted to evaluate the clinical utility of LAP monitoring in patients with heart failure.
Journal of Cardiovascular Translational Research | 2011
Richard W. Troughton; Jay Ritzema; Iain Melton; Henry Krum; Philip B. Adamson; Saibal Kar; Prediman K. Shah; James S. Whiting; J. Thomas Heywood; Spencer Rosero; Jagmeet P. Singh; Leslie A. Saxon; Ray V. Matthews; Ian Crozier; William T. Abraham
Jacc-cardiovascular Imaging | 2011
Jay Ritzema; A. Mark Richards; Ian Crozier; Christopher F. Frampton; Iain Melton; Robert N. Doughty; James T. Stewart; James S. Whiting; William T. Abraham; Richard W. Troughton
Heart Lung and Circulation | 2008
Jay Ritzema; Mark Richards; Ian Crozier; Nicola Gardiner; Iain Melton; Robert N. Doughty; James S. Whiting; William T. Abraham; R. Troughton
Heart Lung and Circulation | 2008
Re Park; Jay Ritzema; Iain Melton; Ian Crozier; A.M. Richards; R. Troughton
Heart Lung and Circulation | 2007
Jay Ritzema; R. Troughton; Iain Melton; Robert N. Doughty; Jim Stewart; Henry Krum; Anthony Walton; James S. Whiting; William T. Abraham
Heart Lung and Circulation | 2007
Jay Ritzema; Mark Richards; Gary Nicholls; C. M. Frampton; Iain Melton; Ian Crozier; Robert N. Doughty; William T. Abraham; R. Troughton
Heart Lung and Circulation | 2007
Jay Ritzema; Iain Melton; Ian Crozier; Robert N. Doughty; Henry Krum; Anthony Walton; William T. Abraham; R. Troughton
Heart Lung and Circulation | 2007
Jay Ritzema; R. Troughton; Iain Melton; Robert N. Doughty; Jim Stewart; Henry Krum; Anthony Walton; James S. Whiting; William T. Abraham