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Liverpool, United Kingdom

Perera D.,Kings College London | Stables R.,Liverpool Heart and Chest Hospital | Clayton T.,London School of Hygiene and Tropical Medicine | De Silva K.,Kings College London | And 4 more authors.
Circulation | Year: 2013

BACKGROUND - : There is conflicting evidence on the utility of elective intra-aortic balloon pump (IABP) use during high-risk percutaneous coronary intervention (PCI). Observational series have indicated a reduction in major in-hospital adverse events, although randomized trial evidence does not support this. A recent study has suggested a mortality benefit trend early after PCI, but there are currently no long-term outcome data from randomized trials in this setting. METHODS AND RESULTS - : Three hundred one patients with left ventricular impairment (ejection fraction <30%) and severe coronary disease (BCIS-1 jeopardy score ≥8; maximum possible score=12) were randomized to receive PCI with elective IABP support (n=151) or without planned IABP support (n=150). Long-term all-cause mortality was assessed by tracking the databases held at the Office of National Statistics (in England and Wales) and the General Register Office (in Scotland). The groups were balanced in terms of baseline characteristics (left ventricular ejection fraction, 23.6%; BCIS-1 jeopardy score, 10.4) and the amount and type of revascularization performed. Mortality data were available for the entire cohort at a median of 51 months (interquartile range, 41-58) from randomization. All-cause mortality at follow-up was 33% in the overall cohort, with significantly fewer deaths occurring in the elective IABP group (n=42) than in the group that underwent PCI without planned IABP support (n=58) (hazard ratio, 0.66; 95% confidence interval, 0.44-0.98; P=0.039). CONCLUSIONS - : In patients with severe ischemic cardiomyopathy treated with PCI, all-cause mortality was 33% at a median of 51 months. Elective IABP use during PCI was associated with a 34% relative reduction in all-cause mortality compared with unsupported PCI. © 2013 American Heart Association, Inc.

Poullis M.,Liverpool Heart and Chest Hospital
Journal of Extra-Corporeal Technology | Year: 2012

Aortic root and valve clots are rare but well described in patients on maximal left ventricular assist device (LVAD) support. We performed a theoretical analysis using computational fluid dynamic analyses in two dimensions to try and ascertain if inflow cannula design/orientation/placement affect aortic root flow dynamics. Two-dimensional computational fluid dynamics using easy CFD-G was performed. The effect of a curved inflow cannula, a straight cannula, and one with a hole in the outer curve was analyzed. In addition, the effect of inflow conduit angulation on the ascending aorta was studied. Computational fluid dynamic (CFD) analysis predicts that stagnant blood exists in the aortic root when little or no cardiac ejection is taking place. Coronary flow is too small to affect the root flow streamlines. A hole on the root side of a curved inflow aortic cannula increases the flow in the aortic root and may decrease the incidence of root and valve thrombosis. The angle of the inflow conduit attachment to the ascending aorta was also found to be crucial with regard to aortic root blood stasis. In addition, a baffle at the tip of the inflow cannula may prove to be beneficial. Theoretical analysis using the technique of CFD predicts that inflow cannula position and design may affect the incidence of aortic root thrombosis during LVAD support when minimal cardiac ejection is occurring.

Poullis M.,Liverpool Heart and Chest Hospital
Interactive Cardiovascular and Thoracic Surgery | Year: 2014

OBJECTIVESTo determine the optimal computed tomography (CT) scanning interval for the detection of a new primary lung cancer and recurrent disease, utilizing the known mathematical formula for tumour doubling.METHODS where: Ti interval time, Diinitial diameter and D ofinal diameter. Three doubling times were utilized for demonstration of the principle, 30, 80 and 100 days.RESULTSA worst-case scenario for a doubling time of 30 days indicates that a 2-mm tumour will need 210 days (7 months) to reach 10 mm in diameter and 300 days (10 months) to reach 20 mm in diameter. Over a 5-year (60 months) follow-up period, this indicates that eight CT scans will be required if a threshold of 10 mm is desired or six if a threshold of 20 mm is desired. For an 80-day doubling time over a 5-year (60 months) follow-up period, three CT scans will be required if a threshold of 10 mm is desired or two if a threshold of 20 mm is desired and for a 100-day doubling time. Assuming complete histological clearance of the primary lung cancer and that recurrence occurs from a microscopic focus, a time period of 1700 days (56 months) is required to reach 10 mm in diameter.CONCLUSIONSThe exact timing of interval CT scanning to detect recurrence and new primary tumour depends on philosophy; however, three monthly CT scanning is probably inappropriate, and scanning every 7 months is probably the shortest interval that is clinically useful, particularly for small-cell lung cancer in the first year after treatment. We recommend, based on mathematical modelling, a scanning interval post-potentially curative resection surgery for primary lung cancer of 18 months, which is different from the current guidelines on surveillance, for non-small-cell lung cancer. © 2013 The Author.

Alkarmi A.,Liverpool Heart and Chest Hospital
Sports medicine (Auckland, N.Z.) | Year: 2010

Coronary angiography and angioplasty are common invasive procedures in cardiovascular medicine, which involve placement of a sheath inside peripheral conduit arteries. Sheath placement and catheterization can be associated with arterial thrombosis, spasm and occlusion. In this paper we review the literature pertaining to the possible benefits of arterial 'prehabilitation'--the concept that interventions aimed at enhancing arterial function and size (i.e. remodelling) should be undertaken prior to cardiac catheterization or artery harvest during bypass graft surgery. The incidence of artery spasm, occlusion and damage is lower in larger arteries with preserved endothelial function. We conclude that the beneficial effects of exercise training on both artery size and function, which are particularly evident in individuals who possess cardiovascular diseases or risk factors, infer that exercise training may reduce complication rates following catheterization and enhance the success of arteries harvested as bypass grafts. Future research efforts should focus directly on examination of the 'prehabilitation' hypothesis and the efficacy of different interventions aimed at reducing clinical complications of common interventional procedures.

Hawkins N.M.,Liverpool Heart and Chest Hospital | Petrie M.C.,Golden Jubilee National Hospital | MacDonald M.R.,Golden Jubilee National Hospital | Jhund P.S.,University of Glasgow | And 3 more authors.
Journal of the American College of Cardiology | Year: 2011

The combination of heart failure and chronic obstructive pulmonary disease presents many therapeutic challenges. The cornerstones of therapy are beta-blockers and beta-agonists, respectively. Their pharmacological effects are diametrically opposed, and each is purported to adversely affect the alternative condition. The tolerability of beta-blockade in patients with mild and fixed airflow obstruction likely extends to those with more severe disease. However, the evidence is rudimentary. The long-term influence of beta-blockade on pulmonary function, symptoms, and quality of life is unclear. Low-dose initiation and gradual up-titration of cardioselective beta-blockers is currently recommended. Robust clinical trials are needed to provide the answers that may finally allay physicians' mistrust of beta-blockers in patients with chronic obstructive pulmonary disease. Beta-agonists are associated with incident heart failure in patients with pulmonary disease and with increased mortality and hospitalization in those with existing heart failure. These purported adverse effects require further investigation. In the meantime, clinicians should consider carefully the etiology of dyspnea and obtain objective evidence of airflow obstruction before prescribing beta-agonists to patients with heart failure. © 2011 American College of Cardiology Foundation.

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