Vakhtang Tchantchaleishvili

Uncorrected pre-operative mitral valve regurgitation is not associated with adverse outcomes after continuous-flow left ventricular assist device implantation

BACKGROUND Mitral valve regurgitation (MR) is prevalent in patients with heart failure. Because very few data exist examining the influence of significant pre-operative MR on outcomes after left ventricular assist device (LVAD) implantation, we evaluate our experience. METHODS Between October 1996 and August 2013, 756 patients underwent primary LVAD implantation at our institutions. Of these, 508 patients received a continuous-flow LVAD and represent the contemporary cohort for this analysis. Devices implanted included the HeartMate II in 410 patients (81%) and HeartWare HVAD in 98 patients (19%). Based on availability of pre-operative echocardiography, 491 patients were divided into 2 study groups according to degree of pre-operative MR; 189 patients (39%) had moderate to severe or greater MR (MR group), and 302 (61%) had less than moderate to severe MR (less MR group). Median age at operation (60 years in MR group vs 58 years in less MR group, p = 0.19), male sex (78% in MR group vs 81% in less MR group, p = 0.42), and ischemic etiology (46% in MR group vs 51% in less MR group, p = 0.35) were similar between groups. RESULTS There were 40 early deaths (7.9%), and follow-up was available in all 468 early survivors for 641 patient-years of support. Patients in the MR group had higher late survival (2 years, 75%; 4 years, 65%) compared with patients in the less MR group (2 years, 66%; 4 years, 48%; p < 0.04). Cox proportional hazards model confirmed the independent interaction between MR and late survival (hazard ratio 0.62, p = 0.04). CONCLUSIONS There was improved survival in patients with severe pre-operative MR after continuous-flow LVAD implantation in our cohort. These findings may lend insight into the possible lack of value of addressing significant MR at the time of LVAD implantation.

Evaluation and treatment of pump thrombosis and hemolysis

Ventricular assist devices (VADs) are not fully biocompatible, and are therefore predisposed to device thrombosis and subsequent pump dysfunction. Clinically significant hemolysis in VADs most often occurs as a result of device thrombosis, but can also be caused by other factors. Herein we describe the evaluation and management of VAD thrombosis and hemolysis.

Six-year integrated cardiothoracic surgery residency applicants: Characteristics, expectations, and concerns

OBJECTIVE During the past 5 years, 6-year integrated cardiothoracic surgery residency programs have increased in number and popularity. METHODS To understand the background and motivation of the applicants for 6-year integrated programs, we surveyed 80 candidates interviewing for Accreditation Council for Graduate Medical Education-accredited 6-year integrated cardiothoracic surgery residency programs for the 2012 match season, with 36 respondents completing the survey. RESULTS The applicants interviewed for 6-year integrated programs had peer-reviewed publications (91.7%) and were interested in academic careers (91.4%), dedicated research time (58.3%), and cardiac surgery (66.7%). The time saved in training was considered an advantage of the 6-year integrated cardiothoracic surgery residency programs, although concern was present about the development of the mature, well-rounded cardiothoracic surgeon. CONCLUSIONS We found that most of the candidates for 6-year integrated cardiothoracic surgery residency were young, high-achieving individuals oriented toward academic careers with a significant interest in dedicated research time and cardiac surgery.

Cannulation‐Related Complications on Veno‐Arterial Extracorporeal Membrane Oxygenation: Prevalence and Effect on Mortality

Cannulation-related complications are a known source of morbidity in patients supported on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Despite its prevalence, little is known regarding the outcomes of patients who suffer such complications. This is a single institution review of cannulation-related complications and its effect on mortality in patients supported on VA-ECMO from January 2010-2015 using three cannulation strategies: axillary, femoral, and central. Complications were defined as advanced if they required major interventions (fasciotomy, amputation, site conversion). Patients were divided into two groups (complication present vs. not present) and Kaplan-Meier analysis was performed to determine any differences in their survival distributions. There were 103 patients supported on VA-ECMO: 41 (40%), 36 (35%), and 26 (25%) were cannulated via axillary, femoral, and central access, respectively. Cannulation-related complications occurred in 33 (32%) patients and this did not differ significantly between either axillary (34%), femoral (36%), or central (23%) strategies (P = 0.52). The most common complications encountered were hemorrhage and limb ischemia in 19 (18%) and 11 (11%) patients. Hemorrhagic complications did not differ between groups (P = 0.37), while limb ischemia and hyperperfusion were significantly associated with femoral and axillary cannulation, at a rate of 25% (P < 0.01) and 15% (P = 0.01), respectively. There was no difference in the incidence of advanced complications between cannulation groups: axillary (12%) vs. femoral (14%) vs. central (8%; P = 0.75). In addition, no increase in mortality was noted in patients who developed a cannulation-related complication by Kaplan-Meier estimates (P = 0.37). Cannulation-related complications affect a significant proportion of patients supported on VA-ECMO but do not differ in incidence between different cannulation strategies and do not affect patient mortality. Improved efforts at preventing these complications need to be developed to avoid the additional morbidity in an already critical patient population.

Ventricular Recovery and Pump Explantation in Patients Supported by Left Ventricular Assist Devices: A Systematic Review.

Several studies have reported that a portion of patients who exhibit cardiac recovery during left ventricular assist device (LVAD) support can have their device explanted with reasonable long-term survival. The aim of this systematic review is to assess the survival and cardiac function in patients with explanted LVADs from the current literature. Electronic search was performed to identify all studies in English literature assessing LVAD explantation. All identified articles were systematically assessed using the inclusion and exclusion criteria. Selected studies were subjected to quantitative assessment. From 5 electronic databases, 11 studies (213 patients) were included. Pooled mean perioperative mortality rate of those explanted was 9.2% (95% CI, 5.0–14.5%; I2 = 0). Pooled mean late mortality rate was 15% (95% CI, 9.0–22.1%; I2 = 31%). The pooled 1, 5, and 10 year survival postexplant was 91, 76, and 65.7%, respectively. Pooled postweaning freedom from heart failure (HF) recurrence reached 81.3%. Subset analysis demonstrated that patients explanted from a continuous-flow LVAD versus pulsatile LVAD had a lower rate of HF recurrence (6.6 vs. 28.3%, p = 0.03) and LVAD reimplantation (7.5 vs. 37%, p = 0.001). Before LVAD explantation, overall mean left ventricular ejection fraction (LVEF) was 49%. Weighted pooled early and late postexplantation mean LVEF was 47.3 and 41.2%, respectively. Late postexplantation LVEF was significantly higher in the continuous-flow versus pulsatile LVAD subgroup (41.5 vs. 24%, p = 0.001). This review shows encouraging safety and 10 year survival outcomes after explantation of LVADs in carefully selected patients, with rates better than expected after a heart transplant. Recovery of the native heart is the most desirable clinical outcome in patients supported with LVADs and should be actively sought.

Clinical implications of physiological flow adjustment in continuous-flow left ventricular assist devices.

There is increasing evidence for successful management of end-stage heart failure with continuous-flow left ventricular assist device (CF-LVAD) technology. However, passive flow adjustment at fixed CF-LVAD speed is susceptible to flow balancing issues as well as adverse hemodynamic effects relating to the diminished arterial pulse pressure and flow. With current therapy, flow cannot be adjusted with changes in venous return, which can vary significantly with volume status. This limits the performance and safety of CF-LVAD. Active flow adjustment strategies have been proposed to improve the synchrony between the pump and the native cardiovascular system, mimicking the Frank–Starling mechanism of the heart. These flow adjustment strategies include modulation by CF-LVAD pump speed by synchrony and maintenance of constant flow or constant pressure head, or a combination of these variables. However, none of these adjustment strategies have evolved sufficiently to gain widespread attention. Herein we review the current challenges and future directions of CF-LVAD therapy and sensor technology focusing on the development of a physiologic, long-term active flow adjustment strategy for CF-LVADs.

Long-term total cardiac support in a Fontan-type circulation with HeartMate II left ventricular assist device

Interest in utilizing long-term mechanical circulatory support for Fontan-type circulation has been high. Unfortunately, so far such attempts have not been successful. Herein, we are presenting the first case of an individual with biventricular heart failure and Fontan-type circulation on long-term mechanical circulatory support with a continuous-flow left ventricular assist device.

Resident Perceptions of 2-Year Versus 3-Year Cardiothoracic Training Programs

BACKGROUND Resident perceptions of 2-year (2Y) vs 3-year (3Y) programs have never been characterized. The objective was to use the mandatory Thoracic Surgery Residents Association and Thoracic Surgery Directors Association In-Training Examination survey to compare perceptions of residents graduating from 2Y vs 3Y cardiothoracic programs. METHODS Each year Accreditation Council for Graduate Medical Education cardiothoracic residents are required to take a 30-question survey designed by the Thoracic Surgery Residents Association and the Thoracic Surgery Directors Association accompanying the In-Training Examination with a 100% response rate. The 2013 and 2014 survey responses of residents graduating from 2Y vs 3Y training programs were compared. The Wilcoxon signed rank test was used to analyze ordinal and interval data. RESULTS Graduating residents completed 167 surveys, including 96 from 2Y (56%) and 71 from 3Y (43%) programs. There was no difference in the perception of being prepared for the American Board of Thoracic Surgery examinations or amount of debt between 2Y and 3Y respondents. There was no difference in intended academic vs private practice. Graduating 3Y residents felt more prepared to meet case requirements and better trained, were more likely to pass their written American Board of Thoracic Surgery examinations, and were less likely to pursue additional training beyond their cardiothoracic residency. CONCLUSIONS There was no difference in field of interest, practice type, and amount of debt between graduating 2Y vs 3Y residents. Respondents from 2Y programs expressed more difficulty in meeting case requirements, whereas residents from 3Y programs felt more prepared for independent practice and had higher American Board of Thoracic Surgery written pass rates.

Late erosion of Amplatzer septal occluder device resulting in cardiac tamponade

Transcatheter device closure of atrial septal defects (ASDs) is a minimally invasive technique that offers an alternative to conventional surgical repair. There are risks imposed by this technique; however, they compare favourably with risks of surgical closure. Here, we present a case of a 59-year old male with late erosion of an Amplatzer septal occluder device resulting in cardiac tamponade 5 years after device placement. To the best of our knowledge, cardiac tamponade this late after device placement has not yet been reported. Septal occlusion device erosion remains a major issue among the risks imposed by device closure of an ASD. More data are needed to better understand its true causes and possible solutions.

Transcatheter aortic valve implantation (TAVI) versus sutureless aortic valve replacement (SUAVR) for aortic stenosis: a systematic review and meta-analysis of matched studies

BACKGROUND With improving technologies and an increasingly elderly populations, there have been an increasing number of therapeutic options available for patients requiring aortic valve replacement. Recent evidence suggests that transcatheter aortic valve implantation (TAVI) is one suitable option for high risk inoperable patients, as well as high risk operable patients. Sutureless valve technology has also been developed concurrently, with facilitates surgical aortic valve replacement (SUAVR) by allow resection and replacement of the native aortic valve with minimal sutures and prosthesis anchoring required. For patients amenable for both TAVI and SUAVR, the evidence is unclear with regards to the benefits and risks of either approach. The objectives are to compare the perioperative outcomes and intermediate-term survival rates of TAVI and SUAVR in matched or propensity score matched studies. METHODS A systematic literature search was performed to include all matched or propensity score matched studies comparing SUAVR versus TAVI for severe aortic stenosis. A meta-analysis with odds ratios (OR) and mean differences were performed to compare key outcomes including paravalvular regurgitation and short and intermediate term mortality. RESULTS Six studies met our inclusion criteria giving a total of 741 patients in both the SUAVR and TAVI arm of the study. Compared to TAVI, SUAVR had a lower incidence of paravalvular leak (OR =0.06; 95% CI: 0.03-0.12, P<0.01). There was no difference in perioperative mortality, however SUAVR patients had significantly better survival rates at 1 (OR =2.40; 95% CI: 1.40-4.11, P<0.01) and 2 years (OR =4.62; 95% CI: 2.62-8.12, P<0.01). CONCLUSIONS The present study supports the use of minimally invasive SUAVR as an alternative to TAVI in high risk patients requiring aortic replacement. The presented results require further validation in prospective, randomized controlled studies.