Research

Saxena A, Virk SA, Bowman S, Bannon PG

J Cardiovasc Surg (Torino) 2017 Mar;

PMID: 28322038

Abstract

BACKGROUND: This systematic review and meta-analysis was performed to evaluate the impact of preoperative atrial fibrillation (preAF) on early and late outcomes after aortic valve replacement (AVR).

METHODS: Medline, EMBASE, and CENTRAL were systematically searched for studies that reported AVR outcomes according to the presence or absence of preAF. Data were independently extracted by two investigators; a meta-analysis was conducted according to predefined clinical endpoints. Studies including patients undergoing concomitant atrial fibrillation surgery were excluded.

RESULTS: Six observational studies with 8 distinct AVR cohorts (AVR ± concomitant surgery) met criteria for inclusion, including a total of 6693 patients. Of these, 1014 (15%) presented with preAF. Overall, peri-operative mortality was increased in patients with preAF (odds ratio [OR] 2.33; 95% CI, 1.48 – 3.67; p<0.001). Subgroup analysis of patients undergoing isolated AVR also demonstrated preAF as a risk factor for peri-operative mortality (OR 2.49; 95% CI, 1.57-3.95; p<0.001). PreAF was also associated with acute renal failure (OR 1.42; 95% CI, 1.07-1.89; p=0.02) but not stroke (OR 1.11; 95% CI, 0.59 - 2.12; p=0.74). Late mortality was significantly higher in patients with preAF (hazard ratio [HR] 1.75; 95% CI, 1.33-2.30; p<0.001). This relationship remained true when only patients who underwent isolated AVR were analyzed (HR 1.97; 95% CI, 1.11-3.51; p=0.02).

CONCLUSIONS: PreAF is associated with an increased risk of early- and late-mortality after AVR. These data support the more widespread utilization of concomitant AF ablation.

Seco M, Zhao DF, Byrom MJ, Wilson MK, Vallely MP, Fraser JF, Bannon PG

Int. J. Cardiol. 2017 May;235:22-32

PMID: 28285802

Abstract

BACKGROUND: This systematic review aimed to evaluate the clinical outcomes and cost-effectiveness of left ventricular assist devices (LVADs) used as bridge to transplantation (BTT), compared to orthotopic heart transplantation (OHT) without a bridge.

METHOD: Systematic searches were performed in electronic databases with available data extracted from text and digitized figures. Meta-analysis of short and long-term term post-transplantation outcomes was performed with summation of cost-effectiveness analyses.

RESULTS: Twenty studies reported clinical outcomes of 4575 patients (1083 LVAD BTT and 3492 OHT). Five studies reported cost-effectiveness data on 837 patients (339 VAD BTT and 498 OHT). There was no difference in long-term post-transplantation survival (HR 1.24, 95% CI 1.00-1.54), acute rejection (HR 1.10, 95% CI 0.93-1.30), or chronic rejection and cardiac allograft vasculopathy (HR 0.99, 95% CI 0.73-1.36). No differences were found in 30-day post-operative mortality (OR 0.91, 95% CI 0.42-2.00), stroke (OR 1.64, 95% CI 0.43-6.27), renal failure (OR 1.43, 95% CI 0.58-3.54), bleeding (OR 1.56, 95% CI 0.78-3.13), or infection (OR 2.44, 95% CI 0.81-7.38). Three of the five studies demonstrated incremental cost-effectiveness ratios below the acceptable maximum threshold. The total cost of VAD BTT ranged from $316,078 to $1,025,500, and OHT ranged from $179,051 to $802,200.

CONCLUSION: LVADs used as BTT did not significantly alter post-transplantation long-term survival, rejection, and post-operative morbidity. LVAD BTT may be cost-effective, particularly in medium and high-risk patients with expected prolonged waiting times, renal dysfunction, and young patients.

Ramponi F, Jeremy RW, Wilson MK

J Card Surg 2017 Apr;32(4):259-261

PMID: 28271560

Abstract

We present a patient with Takayasu arteritis and severe aortic valve regurgitation and bilateral carotid artery occlusions, who underwent aortic valve replacement and aorto-bicarotid bypass. The management of the cardiovascular manifestations of Takayasu arteritis is reviewed.

Stevens MC, Callaghan FM, Forrest P, Bannon PG, Grieve SM

J Biomech 2017 Apr;55:64-70

PMID: 28262284

Abstract

Peripheral veno-arterial extra-corporeal membrane oxygenation (ECMO) is an artificial circulation that supports patients with severe cardiac and respiratory failure. Differential hypoxia during ECMO support has been reported, and it has been suggested that it is due to the mixing of well-perfused retrograde ECMO flow and poorly-perfused antegrade left ventricle (LV) flow in the aorta. This study aims to quantify the relationship between ECMO support level and location of the mixing zone (MZ) of the ECMO and LV flows. Steady-state and transient computational fluid dynamics (CFD) simulations were performed using a patient-specific geometrical model of the aorta. A range of ECMO support levels (from 5% to 95% of total cardiac output) were evaluated. For ECMO support levels above 70%, the MZ was located in the aortic arch, resulting in perfusion of the arch branches with poorly perfused LV flow. The MZ location was stable over the cardiac cycle for high ECMO flows (>70%), but moved 5cm between systole and diastole for ECMO support level of 60%. This CFD approach has potential to improve individual patient care and ECMO design.

Indja B, Seco M, Seamark R, Kaplan J, Bannon PG, Grieve SM, Vallely MP

Heart Lung Circ 2017 Feb;

PMID: 28237537

Abstract

Neurocognitive and psychiatric complications are common following cardiac surgery and impact on patient quality of life, recovery from surgery, participation in rehabilitation and long-term mortality. Postoperative cognitive decline, depressive disorders, post-traumatic stress disorder and neurocognitive impairment related to silent brain infarcts have all been linked to the perioperative period of cardiac surgery, and potentially have serious consequences. The accurate assessment of these conditions, particularly in determining the aetiology, and impact on patients is difficult due to the poorly recognised nature of these complications as well as similarities in presentation with postoperative delirium. This review aims to summarise current understanding surrounding psychiatric disturbances following cardiac surgery including the impact on patient quality of life and long-term outcomes.

Zhao DF, Edelman JJ, Seco M, Bannon PG, Wilson MK, Byrom MJ, Thourani V, Lamy A, Taggart DP, Puskas JD, Vallely MP

J. Am. Coll. Cardiol. 2017 Feb;69(8):924-936

PMID: 28231944

Abstract

BACKGROUND: Coronary artery bypass grafting (CABG) remains the standard of treatment for 3-vessel and left main coronary disease, but is associated with an increased risk of post-operative stroke compared to percutaneous coronary intervention. It has been suggested that CABG techniques that eliminate cardiopulmonary bypass and reduce aortic manipulation may reduce the incidence of post-operative stroke.

OBJECTIVES: A network meta-analysis was performed to compare post-operative outcomes between all CABG techniques, including anaortic off-pump CABG (anOPCABG), off-pump with the clampless Heartstring device (OPCABG-HS), off-pump with a partial clamp (OPCABG-PC), and traditional on-pump CABG with aortic cross-clamping.

METHODS: A systematic search of 6 electronic databases was performed to identify all publications reporting the outcomes of the included operations. Studies reporting the primary endpoint, 30-day post-operative stroke rate, were included in a Bayesian network meta-analysis.

RESULTS: There were 13 included studies with 37,720 patients. At baseline, anOPCABG patients had higher previous stroke than did the OPCABG-PC (7.4% vs. 6.5%; p = 0.02) and CABG (7.4% vs. 3.2%; p = 0.001) patients. AnOPCABG was the most effective treatment for decreasing the risk of post-operative stroke (-78% vs. CABG, 95% confidence interval [CI]: 0.14 to 0.33; -66% vs. OPCABG-PC, 95% CI: 0.22 to 0.52; -52% vs. OPCABG-HS, 95% CI: 0.27 to 0.86), mortality (-50% vs. CABG, 95% CI: 0.35 to 0.70; -40% vs. OPCABG-HS, 95% CI: 0.38 to 0.94), renal failure (-53% vs. CABG, 95% CI: 0.31 to 0.68), bleeding complications (-48% vs. OPCABG-HS, 95% CI: 0.31 to 0.87; -36% vs. CABG, 95% CI: 0.42 to 0.95), atrial fibrillation (-34% vs. OPCABG-HS, 95% CI: 0.49 to 0.89; -29% vs. CABG, 95% CI: 0.55 to 0.87; -20% vs. OPCABG-PC, 95% CI: 0.68 to 0.97), and shortening the length of intensive care unit stay (-13.3 h; 95% CI: -19.32 to -7.26; p < 0.0001).

CONCLUSIONS: Avoidance of aortic manipulation in anOPCABG may decrease the risk of post-operative stroke, especially in patients with higher stroke risk. In addition, the elimination of cardiopulmonary bypass may reduce the risk of short-term mortality, renal failure, atrial fibrillation, bleeding, and length of intensive care unit stay.

Kozman MA, Parikh RN, Fisher OM

ANZ J Surg 2017 Feb;

PMID: 28219119

Abstract

Lin L, Sherrah A, Vallely M, Simmons L

Eur Heart J Cardiovasc Imaging 2017 Feb;

PMID: 28204114

Abstract

Robinson BM, Paterson HS, Denniss AR

Heart Lung Circ 2016 Dec;

PMID: 28117146

Abstract

BACKGROUND: Extended left internal thoracic artery (LITA) harvesting allows maximal grafting to the anterior and lateral walls with a single ITA conduit. This study evaluates outcomes following the use of a LITA Y graft as the primary grafting strategy.

METHODS: Patients who underwent LITA composite Y-grafting (n=198) between 1995 and 2009 were identified from a cardiac surgical database. Follow-up (mean 13.1 years) was obtained by cross-reference with the state death registry and local cardiology databases.

RESULTS: Operative mortality was zero in the 168 patients who underwent isolated CABG and was 3.5% overall. There were no episodes of perioperative myocardial infarction. Kaplan-Meier 10-year survival was 75.9%. Independent predictors of worse late survival were age, diabetes, chronic obstructive pulmonary disease and pre-existing left ventricular dysfunction. There were 53 episodes of post-discharge angiography at an average of 5.8 years post LITA Y grafting. Twenty cases of LITA Y graft failure were identified, predominantly affecting the free limb (n=15). The ratio of symptom driven angiography to Y graft failure increased over time. Eighteen patients required revascularisation, percutaneous intervention in 15 and reoperative coronary bypass in three.

CONCLUSIONS: Left Internal Thoracic Artery Y grafting is a feasible revascularisation strategy with satisfactory outcomes. These are comparable to other arterial composite graft configurations. A LITA Y allows efficient conduit use without compromising the in situ LITA graft.

Edelman J, Wilson MK, Vallely MP, Bannon PG, McKay G, Robertson SJ, Hislop R, Wong C, Cartwright BL, Forrest P, Torzillo PJ

Anaesth Intensive Care 2017 01;45(1):92-93

PMID: 28072941

Abstract

Herein we detail the cases of three patients transferred on veno-arterial extracorporeal membrane oxygenation (VA ECMO) from a tertiary referral hospital to an ECMO centre. We highlight the benefits of such a transfer and offer this as a model of care for unwell patients likely to require a prolonged period of ECMO support.