Modelled impact of virtual fractional flow reserve in patients undergoing coronary angiography (VIRTU-4).

BACKGROUND: The practical application of 'virtual' (computed) fractional flow reserve (vFFR) based on invasive coronary angiogram (ICA) images is unknown. The objective of this cohort study was to investigate the potential of vFFR to guide the management of unselected patients undergoing ICA. The hypothesis was that it changes management in >10% of cases. METHODS: vFFR was computed using the Sheffield VIRTUheart system, at five hospitals in the North of England, on 'all-comers' undergoing ICA for non-ST-elevation myocardial infarction acute coronary syndrome (ACS) and chronic coronary syndrome (CCS). The cardiologists' management plan (optimal medical therapy, percutaneous coronary intervention (PCI), coronary artery bypass surgery or 'more information required') and confidence level were recorded after ICA, and again after vFFR disclosure. RESULTS: 517 patients were screened; 320 were recruited: 208 with ACS and 112 with CCS. The median vFFR was 0.82 (0.70-0.91). vFFR disclosure did not change the mean number of significantly stenosed vessels per patient (1.16 (±0.96) visually and 1.18 (±0.92) with vFFR (p=0.79)). A change in intended management following vFFR disclosure occurred in 22% of all patients; in the ACS cohort, there was a 62% increase in the number planned for medical management, and in the CCS cohort, there was a 31% increase in the number planned for PCI. In all patients, vFFR disclosure increased physician confidence from 8 of 10 (7.33-9) to 9 of 10 (8-10) (p<0.001). CONCLUSION: The addition of vFFR to ICA changed intended management strategy in 22% of patients, provided a detailed and specific 'all-in-one' anatomical and physiological assessment of coronary artery disease, and was accompanied by augmentation of the operator's confidence in the treatment strategy.

Management of acute aortic dissection in critical care.

Aortic dissections are associated with significant mortality and morbidity, with rapid treatment paramount. They are caused by a tear in the intimal lining of the aorta that extends into the media of the wall. Blood flow through this tear leads to the formation of a false passage bordered by the inner and outer layers of the media. Their diagnosis is challenging, with most deaths caused by aortic dissection diagnosed at post-mortem. Aortic dissections are classified by location and chronicity, with management strategies depending on the nature of the dissection. The Stanford method splits aortic dissections into type A and B, with type A dissections involving the ascending aorta. De Bakey classifies dissections into I, II or III depending on their origin and involvement and degree of extension. The key to diagnosis is early suspicion, appropriate imaging and rapid initiation of treatment. Treatment focuses on initial resuscitation, transfer (if possible and required) to a suitable specialist centre, strict blood pressure and heart rate control and potentially surgical intervention depending on the type and complexity of the dissection. Effective post-operative care is extremely important, with awareness of potential post-operative complications and a multi-disciplinary rehabilitation approach required. In this review article we will discuss the aetiology and classifications of aortic dissection, their diagnosis and treatment principles relevant to critical care. Critical care clinicians play a key part in all these steps, from diagnosis through to post-operative care, and thus a thorough understanding is vital.

Aortic arch replacement with simultaneous antegrade cerebral and systemic perfusion using a single centrifugal pump driven 'split arterial line' extracorporeal circuit design.

The ability to provide antegrade cerebral and systemic perfusion simultaneously may negate the requirement for any prolonged period of circulatory arrest during complex aortic arch reconstruction procedures, depending on the cannulation strategy. We describe the development and successful implementation of a custom 'split arterial line' extracorporeal circuit configuration to facilitate complex aortic surgery. This circuit design offers a wide range of cannulation and perfusion strategies, is safe, adaptable, simple to manage, and avoids the use of roller pumps for blood delivery, which are associated with deleterious haematological complications during prolonged cardiopulmonary bypass cases. The split arterial line approach has now become the standardised methodology for facilitating complex aortic surgery at our institution.

Early Hemodynamic Performance of the Crown PRT Aortic Prosthesis: A Prospective Study.

BACKGROUND: Currently, only limited data are available on the rate of hemodynamic progression with clinical outcome in patients receiving the latest Crown PRT aortic prosthesis. The study aim was to report clinical and hemodynamic outcomes in 55 consecutive patients for a follow up of up to one year after Crown PRT implantation. METHODS: Between February and September 2015, a total of 55 patients (34 males, 21 females; mean age 77.3 ± 1.2 years) underwent aortic valve replacement (AVR) with the latest LivaNova Crown PRT bioprosthesis at the authors' institution. Left ventricular function was preserved in 79% of patients. Data relating to the patients' clinical, echocardiographic and functional capacities were obtained prospectively. RESULTS: There were no in-hospital deaths. Significant perioperative complications included stroke (3.6%), atrial fibrillation (27%), and permanent pacemaker insertion (1.8%). Pre-discharge echocardiography demonstrated peak (PG) and mean (MG) transprosthetic gradients of 24.4 ± 10.4 mmHg and 12.9 ± 6.2 mmHg, respectively. The Doppler velocity index (DVI) was 0.49 ± 0.13, and the effective orifice area index (EOAi) 0.89 ± 0.12 cm2/m2. At a mean follow up of 1.3 ± 0.3 years, the transprosthetic gradients, DVI and EOAi were not significantly different from postoperative or pre-discharge values. The patients' NYHA status was I or II in 95% of cases, and the mean left ventricular mass had decreased by 36% at the end of follow up. CONCLUSIONS: The Crown PRT is an effective bioprosthesis, with a low incidence of valve-related complications comparable to those of other current bioprostheses. The bioprosthesis demonstrated satisfactory results in terms of hemodynamics and freedom from reoperation.

Initial experience with xenograft bioconduit for the treatment of complex prosthetic valve endocarditis.

INTRODUCTION: The treatment of complex prosthetic valve endocarditis (PVE) with aortic root abscess remains a surgical challenge. Several studies support the use of biological tissues to minimize the risk of recurrent infection. We present our initial surgical experience with the use of an aortic xenograft conduit for aortic valve and root replacement. METHODS: Between October 2013 and August 2015, 15 xenograft bioconduits were implanted for complex PVE with abscess (13.3% female). In 6 patients, concomitant procedures were performed: coronary bypass (n=1), mitral valve replacement (n=5) and tricuspid annuloplasty (n=1). The mean age at operation was 60.3±15.5 years. The mean Logistic European system for cardiac operating risk evaluation (EuroSCORE) was 46.6±23.6. The median follow-up time was 607±328 days (range: 172-1074 days). RESULTS: There were two in-hospital deaths (14.3% mortality), two strokes (14.3%) and seven patients required permanent pacemaker insertion for conduction abnormalities (46.7%). The mean length of hospital stay was 26 days. At pre-discharge echocardiography, the conduit mean gradient was 9.3±3.3mmHg and there was either none (n=6), trace (n=6) or mild aortic insufficiency (n=1). There was no incidence of mid-term death, prosthesis-related complications or recurrent endocarditis. CONCLUSIONS: Xenograft bioconduits may be safe and effective for aortic valve and root replacement for complex PVE with aortic root abscess. Although excess early mortality reflects the complexity of the patient population, there was good valve hemodynamics, with no incidence of recurrent endocarditis or prosthesis failure in the mid-term. Our data support the continued use and evaluation of this biological prosthesis in this high-risk patient cohort.

Early in-vivo hemodynamic comparison of supra-annular aortic bioprostheses: Trifecta versus Perimount Magna Ease.

BACKGROUND AND AIM OF THE STUDY: The study aim was to compare early postoperative hemodynamic gradients after supra-annular implantation of the Trifecta and Perimount Magna Ease aortic bioprostheses. METHODS: Between January 2010 and December 2011, a total of 235 patients (105 males, 130 females; mean age at surgery 73.8 +/- 10.2 years) underwent supra-annular aortic valve replacement (AVR), with or without concomitant procedures. The patients were divided into 2 groups receiving either the Perimount Magna Ease (n = 117) or Trifecta (n = 118). Concomitant procedures were performed in 133 patients (56.6%), and 25 procedures (10.6%) were redos. Patients with postoperative severe left ventricular dysfunction and moderate to severe mitral regurgitation were excluded. Gradients were calculated pre-discharge using transthoracic echocardiography. Effective orifice area calculations were not performed. Data were collected retrospectively from hospital databases and analyzed using SPSS 17. RESULTS: Both groups compared well for 14 variables. Group A had a higher number of redo operations and the patients were younger. Postoperative peak and mean gradients (in mmHg) for the Magna Ease group versus Trifecta group were: 19 mm valves, 33.5 +/- 16 versus 24.7 +/- 10 (p = 0.11) and 17.4 +/- 6.5 versus 12.7 +/- 4.4 (p = 0.05); 21 mm, 27.2 +/- 9.1 versus 21.8 +/- 7.2 (p = 0.001) and 13.8 +/- 4.7 versus 10.7 +/- 3.4 (p = 0.001); 23 mm, 25.6 +/- 7.8 versus 20.1 +/- 7.9 (p = 0.005) and 13 +/- 4 versus 10.1 +/- 4.3 (p = 0.002); 25 mm, 22.3 +/- 7.8 versus 15.6 +/- 5.1 (p = 0.01) and 12.8 +/- 4.1 versus 8 +/- 2.8 (p = 0.02). The overall mortality was 3.4%. The median hospital stay was nine days in both groups (p = 0.13). Mortality (p = 0.5), and incidences of perioperative stroke (p = 0.45), postoperative new-onset atrial fibrillation (p = 0.26) and permanent pacemaker implantation (p = 0.8) were similar in both groups. CONCLUSION: Early postoperative gradients were significantly lower in patients receiving Trifecta valves, although the long-term clinical outcome and durability of the valve will require further evaluation.