Peter Ruygrok

Auckland District Health Board, Окленд, Auckland, New Zealand

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Publications (267)1019.63 Total impact

  • T. Wang · D. Choi · G. Gamble · T. Ramanathan · P. Ruygrok
    Heart, Lung and Circulation 12/2015; 24:S96. DOI:10.1016/j.hlc.2015.04.114 · 1.44 Impact Factor
  • Heart, Lung and Circulation 12/2015; 24:S108. DOI:10.1016/j.hlc.2015.04.148 · 1.44 Impact Factor
  • T. Wang · D. Choi · T. Ramanathan · P. Ruygrok
    Heart, Lung and Circulation 12/2015; 24:S96. DOI:10.1016/j.hlc.2015.04.115 · 1.44 Impact Factor
  • Heart, Lung and Circulation 12/2015; 24:S88. DOI:10.1016/j.hlc.2015.04.095 · 1.44 Impact Factor
  • T. Wang · T. Ramanathan · D. Choi · P. Ruygrok
    Heart, Lung and Circulation 12/2015; 24:S96-S97. DOI:10.1016/j.hlc.2015.04.116 · 1.44 Impact Factor
  • Heart, Lung and Circulation 12/2015; 24:S206. DOI:10.1016/j.hlc.2015.06.226 · 1.44 Impact Factor
  • Timothy Watson · Adele Pope · Niels van Pelt · Peter N. Ruygrok
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 10/2015; 42(5):448-449. DOI:10.14503/THIJ-14-4671 · 0.65 Impact Factor
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    ABSTRACT: Background Coronary angiography is the gold standard for assessing coronary artery disease (CAD). In many patients with chest pain, no or mild CAD (< 50% stenosis) is found. It is uncertain whether this ‘non-significant’ result influences management and outcomes. We reviewed characteristics and outcomes in a contemporary cohort of chest pain referrals who had mild or absent CAD on coronary angiography.Method All patients undergoing coronary angiography at Auckland City Hospital during July 2010–October 2011 were reviewed (n = 2983). Of these, 12.3% (n = 366) underwent coronary angiography for evaluation of chest pain and were found to have absent or mild CAD. These patients were followed up for 2.3 ± 0.6 years.ResultsMean age was 60.0 ± 12.3 years, 56.1% were female. The ECG was abnormal in 55.0% of patients. Stress testing for inducible ischaemia was undertaken in 40.7% of patients and was abnormal in 57.7%. Following angiography, 43.2% had no changes to cardiac medications. Additional drug therapy (aspirin, statin, beta-blockers, ACE-inhibitor) was commenced in around 14.2–22.1% of cases. These drugs were discontinued in 4.1–8.2% of patients. Rates of major adverse cardiovascular events and readmissions with chest pain were 0.3% (1) and 1.9% (7) respectively at 30 days, and 1.9% (7) and 6.0% (22) at 1 year.Conclusion Although even non-obstructive atheroma may justify medical therapy to limit disease progression, our findings may suggest that in these cases, invasive coronary angiography, may not lead to the patient/physician reassurance justified by historical data.
    International Journal of Clinical Practice 08/2015; DOI:10.1111/ijcp.12723 · 2.57 Impact Factor
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    ABSTRACT: Evidence from animal models suggest that t-tubule changes may play an important role in the contractile deficit associated with heart failure. However samples are usually taken at random with no regard as to regional variability present in failing hearts which leads to uncertainty in the relationship between contractile performance and possible t-tubule derangement. Regional contraction in human hearts was measured by tagged cine MRI and model fitting. At transplant, failing hearts were biopsy sampled in identified regions and immunocytochemistry was used to label t-tubules and sarcomeric z-lines. Computer image analysis was used to assess 5 different unbiased measures of t-tubule structure/organization. In regions of failing hearts that showed good contractile performance, t-tubule organization was similar to that seen in normal hearts, with worsening structure correlating with the loss of regional contractile performance. Statistical analysis showed that t-tubule direction was most highly correlated with local contractile performance, followed by the amplitude of the sarcomeric peak in the Fourier transform of the t-tubule image. Other area based measures were less well correlated. We conclude that regional contractile performance in failing human hearts is strongly correlated with the local t-tubule organization. Cluster tree analysis with a functional definition of failing contraction strength allowed a pathological definition of 't-tubule disease'. The regional variability in contractile performance and cellular structure is a confounding issue for analysis of samples taken from failing human hearts, although this may be overcome with regional analysis by using tagged cMRI and biopsy mapping. Copyright © 2015. Published by Elsevier Ltd.
    Journal of Molecular and Cellular Cardiology 05/2015; 84. DOI:10.1016/j.yjmcc.2015.04.022 · 4.66 Impact Factor
  • Jonathon M White · Boris S Lowe · Peter N Ruygrok
    JACC. Cardiovascular Interventions 04/2015; 8(5):e77-9. DOI:10.1016/j.jcin.2014.11.026 · 7.35 Impact Factor
  • The New Zealand medical journal 02/2015; 128(1409):78-81.
  • J. Sathananthan · H. Pilmore · J. De Zoysa · P. Ruygrok
    Heart, Lung and Circulation 12/2014; 23:e7. DOI:10.1016/j.hlc.2014.04.146 · 1.44 Impact Factor
  • T. Wang · R. Stewart · D. Choi · G. Gamble · D. Haydock · P. Ruygrok
    Heart, Lung and Circulation 12/2014; 23:e14. DOI:10.1016/j.hlc.2014.04.162 · 1.44 Impact Factor
  • Jonathon M White · Peter N Ruygrok
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    ABSTRACT: The intra-aortic balloon pump (IABP) remains the most widely used form of mechanical circulatory support in current clinical practice. This article will review the current evidence to guide IABP use, focussing on a large registry and prospective, randomised data, and seek to establish appropriate roles for the IABP in contemporary practice. Despite a paucity of clinical evidence, the IABP remains a useful clinical tool in selected settings, although its routine, up-front use in relatively unselected MI populations is not supported by data. Although current evidence no longer supports routine use in certain high-risk groups, further studies of appropriately selected high-risk patients may yet demonstrate benefit in patients with moderate-severe degrees of shock.
    Heart, Lung and Circulation 12/2014; 24(4). DOI:10.1016/j.hlc.2014.12.003 · 1.44 Impact Factor
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    ABSTRACT: Risk models play an important role in stratification of patients for cardiac surgery, but their prognostic utilities for post-operative complications are rarely studied. We compared the EuroSCORE, EuroSCORE II, Society of Thoracic Surgeon's (STS) Score and an Australasian model (Aus-AVR Score) for predicting morbidities after aortic valve replacement (AVR), and also evaluated seven STS complications models in this context. We retrospectively calculated risk scores for 620 consecutive patients undergoing isolated AVR at Auckland City Hospital during 2005-2012, assessing their discrimination and calibration for post-operative complications. Amongst mortality scores, the EuroSCORE was the best at discriminating stroke (c-statistic 0.845); the EuroSCORE II at deep sternal wound infection (c=0.748); and the STS Score at composite morbidity or mortality (c=0.666), renal failure (c=0.634), ventilation>24hours (c=0.732), return to theatre (c=0.577) and prolonged hospital stay >14 days post-operatively (c=0.707). The individual STS complications models had a marginally higher c-statistic (c=0.634-0.846) for all complications except mediastinitis, and had good calibration (Hosmer-Lemeshow test P-value 0.123-0.915) for all complications. The STS Score was best overall at discriminating post-operative complications and their composite for AVR. All STS complications models except for deep sternal wound infection had good discrimination and calibration for post-operative complications. Copyright © 2014 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.
    Heart, Lung and Circulation 12/2014; 24(6). DOI:10.1016/j.hlc.2014.11.021 · 1.44 Impact Factor
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    ABSTRACT: Confocal laser scanning microscopy and super-resolution microscopy provide high-contrast and high-resolution fluorescent imaging, which has great potential to increase the diagnostic yield of endomyocardial biopsy (EMB). EMB is currently the gold standard for identification of cardiac allograft rejection, myocarditis, and infiltrative and storage diseases. However, standard analysis is dominated by low-contrast bright-field light and electron microscopy (EM); this lack of contrast makes quantification of pathological features difficult. For example, assessment of cardiac allograft rejection relies on subjective grading of H&E histology, which may lead to diagnostic variability between pathologists. This issue could be solved by utilising the high contrast provided by fluorescence methods such as confocal to quantitatively assess the degree of lymphocytic infiltrate. For infiltrative diseases such as amyloidosis, the nanometre resolution provided by EM can be diagnostic in identifying disease-causing fibrils. The recent advent of super-resolution imaging, particularly direct stochastic optical reconstruction microscopy (dSTORM), provides high-contrast imaging at resolution approaching that of EM. Moreover, dSTORM utilises conventional fluorescence dyes allowing for the same structures to be routinely imaged at the cellular scale and then at the nanoscale. The key benefit of these technologies is that the high contrast facilitates quantitative digital analysis and thereby provides a means to robustly assess critical pathological features. Ultimately, this technology has the ability to provide greater accuracy and precision to EMB assessment, which could result in better outcomes for patients.
    Heart Failure Reviews 08/2014; 20(2). DOI:10.1007/s10741-014-9455-6 · 3.79 Impact Factor
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    ABSTRACT: We report a case of a 79-year-old man with hemolytic anemia caused by a small paravalvular leak after aortic valve replacement with mechanical prosthesis. The defect was successfully treated with a vascular plug.
    Journal of Cardiovascular Medicine 08/2014; Publish Ahead of Print. DOI:10.2459/JCM.0000000000000132 · 1.51 Impact Factor
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    ABSTRACT: Aims Primary percutaneous coronary intervention (PCI) is the optimal management for ST segment elevation myocardial infarction (STEMI) patients. We reviewed the largest primary PCI regional service in New Zealand: the Auckland/Northland service based at Auckland City Hospital, to assess patient management, in particular the door to reperfusion times (DTRTs), and predictors of death in hospital. Methods We obtained patient details from a comprehensive prospective database of all primary PCI patients admitted with STEMI from 1/1/12 to 31/12/12 to the Auckland City Hospital cardiac catheterisation laboratory. Of four District Health Boards (DHBs) within the region, two accessed this regional service at all times, and two accessed the Auckland City Hospital cardiac catheterisation laboratory ‘after hours’: all times except for 08:00 to 16:00 hours on Monday to Friday. Results A total of 401 adult patients underwent a primary PCI at the Auckland City Hospital Regional centre for a STEMI presentation, over the 12 months period. The median patient age was 61 years, 77% were male. Overall 183 (46%) (95% CI 41, 51) patients achieved a DTRT of ≤ 90 mins, and 266 (66%) (95% CI 61, 71) a DTRT of ≤ 120mins, with a clear geographical influence to these times. Of 27 patients with direct transfer to the catheter laboratory from the community, the DTRT was ≤ 120 mins in 24 (92%) (95% CI 72, 96) patients. In hospital mortality was 24 (6%) patients (95% CI 4, 9). Conclusions The 2012 Auckland/Northland primary PCI service delivers good outcomes consistent with current Australasian standards. Although geographical isolation complicates door to reperfusion times, these may potentially be improved by more focus on direct transfer to the cardiac catheterisation laboratory, especially directly from the community.
    Heart, Lung and Circulation 07/2014; 24(1). DOI:10.1016/j.hlc.2014.06.016 · 1.44 Impact Factor
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    ABSTRACT: Objective The Coherex-EU Study evaluated the safety and efficacy of PFO closure utilizing novel in-tunnel PFO closure devices. Background Transcatheter closure of patent foramen ovale (PFO) followed the development of transcatheter closure devices designed to patch atrial septal defects (ASDs). The Coherex FlatStent and FlatStent EF devices were designed specifically to treat PFO anatomy. MethodsA total of 95 patients with a clinical indication for PFO closure were enrolled in a prospective, multicenter first in man study at six clinical sites. Thirty-six patients received the first-generation FlatStent study device, and 57 patients received the second-generation FlatStent EF study device, which was modified based on clinical experience during the first 38 cases. Two patients enrolled to receive the first generation did not receive a device. ResultsAt 6 months post-procedure, 45% (17/38) of the intention-to-treat (ITT) cohort receiving the first-generation FlatStent device had complete closure, 26% (10/38) had a trivial residual shunt, and 29% (11/38) had a moderate to large residual shunt. In the ITT cohort receiving the second-generation FlatStent EF device, 76% (43/57) had complete closure, 12% (7/57) had a trivial shunt, and 12% had a moderate to large shunt. Five major adverse events occurred, all without sequelae. Conclusion This initial study of the Coherex FlatStent/FlatStent EF PFO Closure System demonstrated the potential for in-tunnel PFO closure. The in-tunnel Coherex FlatStent EF may offer an alternative to septal repair devices for PFO closure in appropriately selected patients; however, further investigation will be necessary to establish the best use of this device. (c) 2012 Wiley Periodicals, Inc.
    Catheterization and Cardiovascular Interventions 06/2014; 83(7). DOI:10.1002/ccd.24565 · 2.11 Impact Factor
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    ABSTRACT: Atrial fibrillation (AF) is the commonest cardiac arrhythmia, becoming increasingly prevalent as the population ages. There is conflicting information around whether AF is associated with adverse outcomes after aortic valve replacement (AVR) from the few studies that have investigated this. We compared the characteristics and outcomes of patients undergoing AVR with their history of AF. Isolated AVR patients at Auckland City Hospital 2005-2012 were divided into those with and without preoperative AF for comparative analyses. Of 620 consecutive patients, 19.2% (119) had permanent or paroxysmal AF preoperatively. Patients with AF were significantly older (70.5 vs 63.4 years, P < 0.001) and were more likely to be New Zealand European (82.4 vs 68.1%, P = 0.004). They also had higher prevalence of NYHA class III-IV (55.4 vs 37.4%, P = 0.004), inpatient operation (62.1 vs 48.3%, P = 0.008), history of stroke (10.9 vs 5.0%, P = 0.031), lower creatinine clearance (73 vs 82, P = 0.001) and higher EuroSCORE II (5.2 vs 3.4%, P < 0.001). Operative mortality (6.7 vs 2.0%, P = 0.012) and composite morbidity (27.7 vs 16.5%, P = 0.006) were also higher in patients with AF. After adjusting for significant variables, preoperative AF remained an independent predictor of operative mortality with an odds ratio of 3.44 (95% confidence interval 1.29-9.13), composite morbidity of 1.79 (1.05-3.04) and a mortality during follow-up hazards ratio of 2.36 (1.44-3.87). AF was associated with several cardiovascular and cardiac surgery risk factors, but remained independently associated with short- and long-term mortality. AF should be incorporated into cardiac surgery risk models and surgical AF ablation may be considered with AVR.
    Interactive Cardiovascular and Thoracic Surgery 05/2014; 19(2). DOI:10.1093/icvts/ivu128 · 1.16 Impact Factor

Publication Stats

3k Citations
1,019.63 Total Impact Points


  • 2014–2015
    • Auckland District Health Board
      Окленд, Auckland, New Zealand
  • 2011–2015
    • University of Auckland
      • • Faculty of Medical and Health Sciences
      • • Department of Medicine
      • • Department of Physiology
      Окленд, Auckland, New Zealand
  • 2003–2015
    • Auckland City Hospital
      Окленд, Auckland, New Zealand
  • 2010
    • Klinikum Kassel
      Cassel, Hesse, Germany
  • 1999–2009
    • Mercy Angiography
      Окленд, Auckland, New Zealand
  • 2004
    • Alfred Hospital
      Melbourne, Victoria, Australia
  • 1998
    • Sahlgrenska University Hospital
      Goeteborg, Västra Götaland, Sweden
  • 1994–1995
    • Erasmus Universiteit Rotterdam
      • Department of Cardiology
      Rotterdam, South Holland, Netherlands