Cardioprotection with Intralipid During Coronary Artery Bypass Grafting Surgery on Cardiopulmonary Bypass: A Randomized Clinical Trial.

PURPOSE: Coronary artery bypass grafting (CABG) on cardiopulmonary bypass (CPB) is associated with myocardial ischemia-reperfusion injury (IRI), which may limit the benefit of the surgery. Both experimental and clinical studies suggest that Intralipid, a lipid emulsion commonly used for parenteral nutrition, can limit myocardial IRI. We therefore aimed to investigate whether Intralipid administered at reperfusion can reduce myocardial IRI in patients undergoing CABG on CPB. METHODS: We conducted a randomized, double-blind, pilot trial in which 29 adult patients scheduled for CABG were randomly assigned (on a 1:1 basis) to receive either 1.5 ml/kg Intralipid 20% or Ringer's Lactate 3 min before aortic cross unclamping. The primary endpoint was the 72-h area under the curve (AUC) for troponin I. RESULTS: Of the 29 patients randomized, 26 were included in the study (two withdrew consent and one was excluded before surgery). The 72-h AUC for troponin I did not significantly differ between the control and Intralipid group (546437 ± 205518 versus 487561 ± 115724 arbitrary units, respectively; P = 0.804). Other outcomes (including 72-h AUC for CK-MB, C-reactive protein, need for defibrillation, time to extubation, length of ICU and hospital stay, and serious adverse events) were similar between the two groups. CONCLUSION: In patients undergoing CABG on CPB, Intralipid did not limit myocardial IRI compared to placebo. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02807727 (registration date: 16 June 2016).

A Multicenter, Cross-Sectional Quality Improvement Project: The Perioperative Implementation of a Hypertension Protocol by Anesthesiologists.

BACKGROUND: Hypertension is a common risk factor for cardiovascular morbidity and mortality, with a high prevalence in patients presenting for elective surgery. In limited resource environments, patients have poor access to primary care physicians, limiting the efficacy of lifestyle modification for the management of hypertension. In these circumstances, the perioperative period presents a unique opportunity for diagnosis and initiation and/or modification of pharmacotherapy of hypertension. Anesthesiologists are ideally placed to lead this aspect of perioperative medicine. The study objective was for anesthesiologists to identify patients at the preoperative visit with previously undiagnosed or poorly controlled chronic hypertension and follow a simple management algorithm. METHODS: In collaboration with expert physicians, we designed and implemented an algorithm for the diagnosis and management of chronic hypertension. This was a multicenter, cross-sectional quality improvement project in 7 hospitals in the Western Cape, South Africa. On the day before scheduled elective surgery, adult in-patients had 2 sets of blood pressure (BP) readings taken, one by nurses and the other by anesthesiologists, using a noninvasive automated BP device. These were averaged on an electronic database, to diagnose hypertension. Patients with normal BP or well-controlled hypertension required no further management. Those with borderline BP received educational pamphlets. Patients with stage 1 or 2 hypertension were managed with medication according to the algorithm, starting 1 day postoperatively, and provided with educational pamphlets. Patients with stage 3 disease had their surgery postponed and were referred to a physician. The primary outcome was adherence by the anesthesiologist to the algorithm in the diagnosis and management of hypertension. An 80% adherence rate was considered successful implementation. The secondary outcome was the adherence to the algorithm at discharge. RESULTS: Two hundred ninety-eight patients were screened for hypertension. One hundred six patients were eligible for the quality improvement project. Thirty-seven (34.9%) had borderline BP readings, 43 (40.6%) had stage 1, 22 (20.8%) stage 2, and 4 (3.8%) stage 3 hypertension, respectively. The adherence rate by the anesthesiologist in initiating treatment according to the algorithm was 89 of 106 (84.0%; 95% confidence interval [CI, 77.0-91.0). There was full adherence to the algorithm in 59 of 106 (55.5%; 95% CI, 46.2-65.1) at the time of discharge from hospital. CONCLUSIONS: Anesthesiologists successfully implemented a quality improvement project for diagnosis and management of hypertension in the perioperative period. This has the potential to reduce the public health burden of hypertension in limited resource environments. Successful ongoing prescription and follow-up requires cooperation within a multidisciplinary team.

Transesophageal echocardiography in minimally invasive cardiac surgery.

PURPOSE OF REVIEW: Transesophageal echocardiography (TEE) has made its way into the cardiac surgery realm and spurred the development of many interventions. In the domain of minimally invasive cardiac surgery (MICS), TEE has become central to reducing cardiovascular complications. RECENT FINDINGS: Real-time three-dimensional TEE is a key contributor to the safe and precise deployment of the PASCAL mitral valve repair system, which is showing great potential in ongoing studies. The current data on outcomes of transcatheter aortic valve replacement show that preprocedural three-dimensional TEE and multidetector computed tomography (CT) perform similarly in aortic root assessment. Three-dimensional color Doppler TEE has been suggested to be more appropriate in quantifying residual mitral regurgitation and evaluating the success of surgical or percutaneous closure. A three-dimensional TEE-derived aortomitral angle may be valuable in predicting and detecting dynamic left ventricular outflow tract obstruction, thereby enhancing the safety of transcatheter mitral valve replacement. SUMMARY: Advanced imaging modalities are essential for the sustained growth of MICS, particularly with the evolution of novel transcatheter systems. These techniques rely on exceptional imaging quality at all stages of the perioperative period to modify surgical-risk and improve patient outcomes. TEE has the additional benefit of providing real-time information on intrathoracic structures to guide intraoperative management.

Point-of-Care Ultrasound Abnormalities in Late-Onset Severe Preeclampsia: Prevalence and Association With Serum Albumin and Brain Natriuretic Peptide.

BACKGROUND: Pilot studies applying point-of-care ultrasound (POCUS) in preeclampsia indicate the presence of pulmonary interstitial edema, cerebral edema, and cardiac dysfunction. Laboratory markers of oncotic pressure (albumin) and cardiac dysfunction (brain natriuretic peptide [BNP]) may be abnormal, but the clinical application remains unclear. We investigated the prevalence of pulmonary interstitial syndrome (PIS), cardiac dysfunction, and increased optic nerve sheath diameter (ONSD) in late-onset preeclampsia with severe features. The primary aim was to examine the association between PIS or ONSD and maternal serum albumin level. The secondary aims were to explore the association between cardiac dysfunction and PIS, ONSD, BNP, and serum albumin level and between POCUS-derived parameters and a suspicious or pathological cardiotocograph. METHODS: Ninety-five women were enrolled in this prospective observational cohort study. A POCUS examination of lungs, heart, and ONSD was performed. PIS was defined as a bilateral B-line pattern on lung ultrasound and diastolic dysfunction according to an algorithm of the American Society of Echocardiography. ONSD >5.8 mm was interpreted as compatible with raised intracranial pressure (>20 mm Hg). Serum BNP and albumin levels were also measured. RESULTS: PIS, diastolic dysfunction, systolic dysfunction, and raised left ventricular end-diastolic pressure (LVEDP) were present in 23 (24%), 31 (33%), 9 (10%), and 20 (25%) women, respectively. ONSD was increased in 27 (28%) women. Concerning the primary outcome, there was no association between albumin level and PIS (P = .4) or ONSD (P = .63). With respect to secondary outcomes, there was no association between albumin level and systolic dysfunction (P = .21) or raised LVEDP (P = .44). PIS was associated with diastolic dysfunction (P = .02) and raised LVEDP (P = .009; negative predictive value, 85%). BNP level was associated with systolic (P < .001) and diastolic dysfunction (P = .003) and LVEDP (P = .007). No association was found between POCUS abnormalities and a suspicious/pathological cardiotocograph (P = .07). CONCLUSIONS: PIS, diastolic dysfunction, and increased ONSD were common in preeclampsia with severe features. Cardiac ultrasound abnormalities may be more useful than albumin levels in predicting PIS. The absence of PIS may exclude raised LVEDP. The further clinical relevance of PIS and raised ONSD remains to be established. BNP level was associated with cardiac ultrasound abnormalities. Although this study was not designed to directly influence clinical management, the findings suggest that POCUS may serve as a useful adjunct to clinical examination for the obstetric anesthesiologist managing these complex patients.

Cardiac Structure and Function in Morbidly Obese Parturients: An Echocardiographic Study.

BACKGROUND: The increasing prevalence of obesity worldwide is a major threat to global health. Cardiac structural and functional changes are well documented for obesity as well as for pregnancy, but there is limited literature on morbidly obese parturients. We hypothesized that there are both cardiac structural and functional differences between morbidly obese pregnant women and pregnant women of normal body mass index (BMI). METHODS: This prospective cross-sectional study was performed in 2 referral maternity units in Cape Town, South Africa, over a 3-month period. Forty morbidly obese pregnant women of BMI ≥40 kg·m (group O) were compared to 45 pregnant women of BMI ≤30 kg·m (group N). Cardiac structure and function were assessed by transthoracic echocardiography, according to the recommendations of the British Society of Echocardiography. The 2-sample t-test with unequal variances was used for the comparison of the mean values between the groups. RESULTS: Acceptable echocardiographic images were obtained in all obese women. Statistical significance was defined as P < .0225 after applying the Benjamini-Hochberg correction for multiple testing. Mean (standard deviation) mean arterial pressure was higher in group O (91 [8.42] vs 84 [9.49] mm Hg, P < .001). There were no between-group differences in heart rate, stroke volume, or cardiac index (84 [12] vs 79 [13] beats·minute, P = .103; 64.4 [9.7] vs 59.5 [13.5] mL, P = .069; 2551 [474] vs 2729 [623] mL·minute·m, P = .156, for groups O and N, respectively). Stroke volume index was lower, and left ventricular mass was higher in group O (30.14 [4.51] vs 34.25 [7.00] mL·m, P = .003; 152 [24] vs 115 [29] g, P < .001). S' septal was lower in group O (8.43 [1.20] vs 9.25 [1.64] cm·second, P = .012). Considering diastolic function, isovolumetric relaxation time was significantly prolonged in group O (73 [15] vs 61 [15] milliseconds, P < .001). The septal tissue Doppler index E' septal was lower in group O (9.08 [1.69] vs 11.28 [3.18], P < .001). There were no between-group differences in E' average (10.7 [2.3] vs 12.0 [2.7], P = .018, O versus N) or E/E' average (7.85 [1.77] vs 7.27 [1.68], P = .137, O versus N). Right ventricular E'/A' was lower in group O (1.07 [0.47] vs 1.29 [0.32], P = .016). CONCLUSIONS: Cardiac index did not differ between obese pregnant women and those with normal BMI. Their increased left ventricular mass and lower stroke volume index could indicate a limited adaptive reserve. Obese women had minor decreases in septal left ventricular tissue Doppler velocity, but the E/E' average values did not suggest clinically significant diastolic dysfunction.

The Technological Basis of a Balloon-Expandable TAVR System: Non-occlusive Deployment, Anchorage in the Absence of Calcification and Polymer Leaflets.

Leaflet durability and costs restrict contemporary trans-catheter aortic valve replacement (TAVR) largely to elderly patients in affluent countries. TAVR that are easily deployable, avoid secondary procedures and are also suitable for younger patients and non-calcific aortic regurgitation (AR) would significantly expand their global reach. Recognizing the reduced need for post-implantation pacemakers in balloon-expandable (BE) TAVR and the recent advances with potentially superior leaflet materials, a trans-catheter BE-system was developed that allows tactile, non-occlusive deployment without rapid pacing, direct attachment of both bioprosthetic and polymer leaflets onto a shape-stabilized scallop and anchorage achieved by plastic deformation even in the absence of calcification. Three sizes were developed from nickel-cobalt-chromium MP35N alloy tubes: Small/23 mm, Medium/26 mm and Large/29 mm. Crimp-diameters of valves with both bioprosthetic (sandwich-crosslinked decellularized pericardium) and polymer leaflets (triblock polyurethane combining siloxane and carbonate segments) match those of modern clinically used BE TAVR. Balloon expansion favors the wing-structures of the stent thereby creating supra-annular anchors whose diameter exceeds the outer diameter at the waist level by a quarter. In the pulse duplicator, polymer and bioprosthetic TAVR showed equivalent fluid dynamics with excellent EOA, pressure gradients and regurgitation volumes. Post-deployment fatigue resistance surpassed ISO requirements. The radial force of the helical deployment balloon at different filling pressures resulted in a fully developed anchorage profile of the valves from two thirds of their maximum deployment diameter onwards. By combining a unique balloon-expandable TAVR system that also caters for non-calcific AR with polymer leaflets, a powerful, potentially disruptive technology for heart valve disease has been incorporated into a TAVR that addresses global needs. While fulfilling key prerequisites for expanding the scope of TAVR to the vast number of patients of low- to middle income countries living with rheumatic heart disease the system may eventually also bring hope to patients of high-income countries presently excluded from TAVR for being too young.

Clinical outcome of a simplified technique for aortic valve replacement with stentless bioprostheses.

BACKGROUND AND AIM OF THE STUDY: Aortic stentless bioprostheses provide good clinical and hemodynamic results, but may be difficult to implant. Their use is also contraindicated in the presence of a severely calcified aortic root. The study aim was to assess the mid-term results of a simplified implant technique of the Sorin Pericarbon Freedom stentless bioprosthesis (SPF), that allows its use in the presence of severe aortic root calcification. METHODS: Between 2001 and 2007, a total of 51 patients underwent aortic valve replacement (AVR) with the SPF, using a new technique which consisted of standard annular fixation and the fixation of each strut with a single 'U' stitch. The perioperative characteristics, early and late mortality and occurrence of valve-related events were evaluated. The overall mean cross-clamp and cardiopulmonary bypass times were 91.5 +/- 30.2 and 125.3 +/- 44.9 min, respectively, and 77.8 +/- 17.7 and 105.6 +/- 22.8 min, respectively, for AVR (these times were comparable to those required in patients receiving stented valve bioprostheses). The mean follow up period was 40.5 months (range: 3-75 months), and was 100% complete. RESULTS: Hospital mortality was 4% and survival 76.5 +/- 14.5% at six years. Late deaths occurred in eight patients; in four cases this was valve-related (1.9%/patient-year). Freedom from valve-related death and reoperation was 91 +/- 9% and 98 +/- 2% respectively, at six years. The mean transprosthetic gradients were 12.0 +/- 3.4, 9.9 +/- 2.6, 8.7 +/- 4.2, 5.2 +/- 3.9, 4.5 +/- 3.0 and 3.2 +/- 2.7 mmHg for the 19, 21, 23, 25, 27 and 29 mm valve sizes, respectively. No valvular or paravalvular regurgitation was recorded. CONCLUSION: This new implantation technique for the aortic SPF stentless bioprosthesis is simple, effective and versatile, and showed good early results. It may be applicable to other stentless bioprostheses, and also be particularly useful in patients with small aortic annulus and in those with a calcified aortic root.

Preclinical evaluation of a transcatheter aortic valve replacement system for patients with rheumatic heart disease.

AIMS: Cardiac surgery in middle-income countries differs significantly from that in high-income countries regarding prevailing heart valve pathologies and access to cardiac surgery. Typically, rheumatic aortic regurgitation in the absence of calcification by far outweighs stenosis. As such, entirely different transcatheter aortic valve implantation (TAVI) concepts are required for these regions. The aim of the study was to evaluate the five-month performance of the SAT (Strait Access Technologies, Cape Town, South Africa) pericardial TAVI system in the orthotopic aortic position of juvenile sheep. METHODS AND RESULTS: A self-homing, non-occlusive balloon-expandable TAVI system comprising a hollow balloon, stabilising locator trunks, a scalloped CoCr stent with elevating anchorage arms and decellularised, sandwich-crosslinked pericardium was compared with control surgical valves (Edwards PERIMOUNT) in sheep. The implantation period was five months. The tactile placement of the TAVI valves was accomplished without the need for rapid pacing. At termination, no structural degeneration was observed in either group. The TAVIs were well healed with the stent struts largely embedded in tissue. Correlating with sheep growth (weight gain of 40.4±13.0%) during the implantation period, mean transvalvular gradients increased from 3.08±1.95 mmHg to 8.50±5.38 mmHg (p=0.044) after five months. CONCLUSIONS: A single-stage, balloon-expandable, easy to place TAVI system with antigen-depleted and antigen-masked bioprosthetic leaflets promises to address the distinct needs of low- and middle-income countries with regard to TAVI better than conventional systems.

Transoesophageal echocardiography (TOE): contra-indications, complications and safety of perioperative TOE

Transoesophageal echocardiography (TOE) has, in certain clinical situations, become an almost universal monitor and diagnostic tool. In the perioperative environment, TOE is frequently used to guide anaesthetic management and assist with surgical decision making for, but not limited to, cardiothoracic, major vascular and transplant operations. The use of TOE is not limited to the theatre environment being frequently used in outpatient clinics, emergency departments and intensive care settings. Two case reports, one of oesophageal perforation and another of TOE utilization in a patient having previously undergone an oesophagectomy, introduce the need for care while using TOE and highlight the need for vigilance. The safe use of TOE, the potential complications and the suggested contra-indications are then considered together with suggestions for improving the safety of TOE in adult and paediatric patients.

Quadruple valve replacement in a patient with severe rheumatic heart disease.

SummaryWe present a patient with rheumatic heart disease involving all the heart valves. An intraoperative transoesophageal echocardiography confirmed severe mitral stenosis, severe aortic regurgitation, severe tricuspid regurgitation and stenosis, and severe pulmonary stenosis. The patient underwent successful quadruple valve replacement during a single operation at the Groote Schuur Hospital, Cape Town, South Africa. LEARNING POINTS: Rheumatic heart disease can affect all the heart valves including the pulmonary valve.Intraoperative transoesophageal echocardiography is key for diagnosis, monitoring and confirmation of successful surgical result during heart valve surgery.Combined surgical procedure of all four valves is possible though associated with long procedural time.

The effect of preoperative atrial fibrillation on survival following mitral valve repair for degenerative mitral regurgitation.

OBJECTIVE: There is conflicting evidence with regard to the impact of preoperative atrial fibrillation (AF) on the post mitral valve (MV) repair on the early and late outcome. METHODS: A total of 349 patients undergoing various MV repair procedures for degenerative mitral regurgitation (MR) between 1997 and 2003 were studied. Preoperatively, 152 (44%) of these patients were in AF and 197 (56%) patients were in sinus rhythm (SR). The clinical features and the outcome in these two cohorts of patients were compared. RESULTS: The patients in the AF group were older than their counterparts in the SR group (66+/-7 vs 62+/-9 years) (p=0.01), had a higher mean NYHA class score (2.4+/-0.6 vs 2.2+/-0.7) (p=0.04) and were more likely to have impaired left ventricular function (60% vs 36%) (p<0.0001). A similar proportion of patients in the AF (38%) and SR (30%) groups had additional cardiac surgical procedures (p=0.12). Operative mortality was 3.9% in AF group versus 0.5% in SR group (p=0.04), and operative morbidity was 27% versus 17%, respectively (p=0.03). At latest follow up, 4% of patients that were in SR preoperatively developed AF; conversely, 2% of the patients in the AF group converted to SR. The rates of recurrent grade II or III MR (4% vs 5%) (p=0.8) and MV re-operation (2.6% vs 2.5%) (p=1.0) were similar in the AF and SR groups. Kaplan-Meier survival at 7 years was 75+/-6% versus 90+/-3% (p=0.005). On Cox proportional hazards regression model, impaired LV function [(p=0.02), hazard ratio 0.25 (95% confidence intervals (C.I.) 0.078-0.84)] and AF [(p=0.03), hazard ratio 2.70 (95% C.I. 1.09-6.68)] were significant adverse predictors of survival. CONCLUSIONS: This study shows that in patients undergoing MV repair for degenerative MR, preoperative AF has a major negative impact on the early and late survival.