Katharina Huenges

Transapical mitral valved stent implantation: Enhanced survival and decreased paravalvular leakages

BACKGROUND/OBJECTIVES This study presents the recent results of transapical implantation of a new design of a mitral valved stent with up to three months follow-up. METHODS A self-expanding re-designed mitral valved stent was implanted via transapical approach into the beating heart of eight pigs. Echocardiographic- and hemodynamic parameters were assessed before (n=8), at 1h (n=8), at one month (n=6), at two months (n=2), and at three months (n=1) after implantation and a cardiac CT was conducted. RESULTS The stent was successfully deployed in all animals. Two animals died within the first month due to incorrect fixation force. Echocardiographic evaluation showed low gradients (3.9 ± 1.4 mm Hg and 1.9 ± 0.8 mm Hg across the valved stent and aortic valve) and a normal mitral annular plane systolic excursion (1.1 ± 0.2 cm) after one month. No paravalvular leakages (PVL) were detected after 1h. The pulmonary artery pressure did not increase after valved stent implantation (p ≥ 0.106). The pulmonary capillary wedge pressure (PCWP) slightly increased to 16 ± 3 mm Hg after one month (p=0.033). The left ventricular end-diastolic pressure was mildly elevated (15.8 ± 8.6 mm Hg) after one month. CONCLUSIONS Secure deployment and correct position of the valved stents were reproducibly achieved in the off-pump implantation procedure. No paravalvular leakages after 1h as well as low gradients, few stent fractures and a normal longitudinal function after one month were achieved with this newly developed and well-aligned prototype. However, a number of challenges have been identified during this study and potential for improvement has been identified.

Transapical mitral valved stent implantation: comparison between circular and D-shaped design.

AIMS In this study two designs of a self-expanding valved stent were compared after off-pump implantation into the mitral valve to identify the superior one. METHODS AND RESULTS Two designs of a mitral valved stent were tested. The first design is composed of a circular atrial element connected to a tube-shaped ventricular element. In the second design, the atrial element is D-shaped to achieve better anatomical alignment. Prior to in vivo testing, the area with the highest risk of PVL was identified in a hydrostatic in vitro set-up. Subsequently, eight pigs received stents (circular, n=5; D-shaped, n=3) via apical access in the beating heart. Positioning and haemodynamics were evaluated by TEE and invasive pressure measurement pre-implantation, after 1 hr, and at two and four weeks. In vitro testing showed less PVL in the anteromedial region in D-shaped design stents (p<0.001). All stents were successfully deployed in vivo and six animals maintained normal haemodynamics for two weeks or longer. Rotational reorientation of all stents with D-shaped elements was observed. Both groups indicated no clinically relevant gradients over the mitral valved stent. CONCLUSIONS This study demonstrates that the circular design was superior to the D-shaped model after rotational reorientation of the latter occurred.

Unilateral pulmonary oedema after minimally invasive mitral valve surgery: a single-centre experience

OBJECTIVES Unilateral pulmonary oedema (UPE) is a rare but potentially life-threatening complication that has been described after minimally invasive mitral valve surgery (MICS). Over the last 8 years, we have witnessed, in our institution, several cases of severe UPE requiring immediate postoperative extracorporeal life support after MICS. Reviewing the available literature, data regarding this complication after MICS are rare. Consequently, we decided to retrospectively analyse patients scheduled for MICS in our institution. METHODS After approval by our institutional review board, 256 MICS patients were analysed. As a primary end-point, we defined a newly developed UPE, radiographically evident within the first 24 h postoperatively. Secondary end-points were length of stay in the intensive care unit, length of stay in the hospital and in-hospital mortality. Chest radiographs were analysed by an independent consultant of radiology. RESULTS Fifty-one (19.9%) patients showed increased right-sided pulmonary vascular congestion in the 1st postoperative chest radiography performed in the intensive care unit. Five (1.95%) patients immediately required extracorporeal life support after admission to the intensive care unit. Cardiopulmonary bypass time was significantly longer in the UPE group [UPE vs non-UPE 213 (49) vs 196 (43) min; P = 0.013]. More patients with UPE showed a preoperative increase of C-reactive protein >0.4265 mg/dl (P = 0.05). Logistic regression analysis identified a preoperative increase in C-reactive protein >0.4265 mg/dl as well as a prolonged cardiopulmonary bypass time (odds ratio 1.009, 95% confidence level 1.002-1.016; P = 0.014) independent risk factors, significantly associated with the development of UPE (odds ratio 2.583, 95% confidence interval 1.275-5.233; P = 0.008), a prolonged cardiopulmonary bypass time (odds ratio 1.009, 95% confidence interval 1.002-1.016; P = 0.014). The presence of pulmonary hypertension (odds ratio 0.273, 95% confidence interval 0.08-0.84; P = 0.02) seemed to be a protective factor regarding the genesis of UPE. CONCLUSIONS In accordance with the rarely available literature regarding UPE after MICS, our analysis led us to hypothesize the possibility of an inflammatory disposition for UPE. The role of pulmonary hypertension remains unclear in our patient population. Clinical Trials Number NCT02655094.

Ventricular assist device implantation in a young patient with non-compaction cardiomyopathy and hereditary spherocytosis

A case of a 15-year-old female patient with acute heart failure due to non-compaction cardiomyopathy and hereditary anaemia (hereditary spherocytic elliptocytosis) requiring ventricular assist device implantation as a bridge to transplantation is presented. The possible effects of mechanical stress on erythrocytes potentially induced by mechanical circulatory support remains unclear, but it may lead to haemolytic crisis in patients suffering from hereditary anaemia. In our case, ventricular assist device therapy was feasible, and haematological complications did not occur within 6 weeks of bridging our patient to heart transplantation.

Left Ventricular Assist Device Implantation with Concomitant Aortic Valve and Ascending Aortic Replacement

Left ventricular assist device (LVAD) is nowadays a routine therapy for patients with advanced heart failure. We present the case of a 74-year-old male patient who was admitted to our center with terminal heart failure in dilated cardiomyopathy and ascending aortic aneurysm with aortic valve regurgitation. The LVAD implantation with simultaneous aortic valve and supracoronary ascending aortic replacement was successfully performed.

Extracorporeal membrane oxygenation for acute respiratory distress syndrome in adults: an analysis of differences between survivors and non-survivors

Objectives: Over the last decade, extracorporeal membrane oxygenation (ECMO) has become a promising option for patients with severe acute respiratory distress syndrome (ARDS). In this single-center observational cohort study, data from a patient group with severe ARDS treated with ECMO was analyzed. Methods: Data from 46 patients [median age 54 years (18 to 72), male: 65.2%] were evaluated retrospectively between January 2009 and September 2015. Results: Diagnosis leading to ARDS was pneumonia in 63.1% of the patients. The median SOFA Score was 13 (10 to 19) and the median LIS was 3.5 (2.67 to 4). The median duration of ECMO support was 12 days (1 to 86). Twenty-eight patients (60.9%) were successfully weaned from ECMO and 22 patients survived (47.8%). Non-survivors needed significantly more frequent renal replacement therapy (37.5% vs. 18.2%; p<0.01) and transfusion of red blood cell concentrates [0.4 units (0.3 to 1.2) vs. 0.9 units (0.5 to 1.6); p<0.01] during ECMO support compared to patients who survived. Conclusion: This report suggests that ECMO currently allows treatment of severe ARDS with presumed improved survival. The incidence rate of acute kidney injury and transfusion are associated with adverse outcomes.

Outcome of Stable Patients With Acute Myocardial Infarction and Coronary Artery Bypass Surgery Within 48 Hours: A Single‐Center, Retrospective Experience

Background The optimal timing of coronary artery bypass grafting (CABG) in clinically stable patients with acute myocardial infarction who are unsuitable for percutaneous coronary intervention is unclear. We report our experience with early CABG in these patients. Methods and Results Between January 2001 and May 2015, 766 patients with ST‐segment–elevation myocardial infarction (STEMI, n=305) or non‐STEMI (NSTEMI, n=461) not including cardiogenic shock underwent CABG within 48 hours at our department. STEMI patients were younger than non‐STEMI patients (age 65 years [range: 58–72] versus 70 years [range: 62–75], P<0.001) with a lower EuroSCORE II (4.12 [range: 2.75–5.81] versus 4.58 [range: 2.80–7.74], P=0.009). STEMI patients had undergone preoperative percutaneous coronary intervention more often (20.3% versus 7.8%, P<0.001). Time to surgery was shorter in STEMI compared with non‐STEMI patients (5.0 hours [range: 3.2–8.8] versus 11.7 hours [range: 6.4–22.0], P<0.001). No significant differences concerning arterial graft use (93.8% versus 94.8%, P=0.540) or complete revascularization (87.5% versus 83.4%, P=0.121) were observed. The rate of strokes did not differ between the groups (2.0% versus 3.9%, P=0.134). Thirty‐day mortality was lower in STEMI patients (2.7% versus 6.6% P=0.018), especially when CABG was performed within 6 hours (1.8% versus 7.1%, P=0.041). Survival of STEMI and non‐STEMI patients was 94% versus 88% after 1 year (P<0.001), 87% versus 73% after 5 years (P<0.001), and 74% versus 57% after 10 years (P<0.001). Independent predictors of 30‐day and long‐term mortality included preoperatively increased lactate values, age, atrial fibrillation, and reduced left ventricular function. Conclusions Stable STEMI patients showed a lower rate of perioperative complications and better survival compared with non‐STEMI patients when CABG was performed within 48 hours.

Coronary artery bypass surgery within 48 hours after cardiac arrest due to acute myocardial infarction

OBJECTIVES Cardiac arrest (CA) in patients with acute myocardial infarction is associated with a poor prognosis. Due to the additional trauma, risk of stroke and lack of data, coronary artery bypass grafting (CABG) is a controversial revascularization strategy for patients who cannot be treated percutaneously. Against this background, we investigated the outcome of patients from our department with acute myocardial infarction undergoing CABG after CA. METHODS Between January 2001 and January 2015, 129 patients with preoperative CA due to acute myocardial infarction underwent CABG at our institution within 48 h after the CA had occurred. Predictors of in-hospital and long-term mortality were analysed. Neurological outcome according to cerebral performance category scale was investigated. RESULTS Sixty CA (47%) events occurred out-of-hospital. Ventricular fibrillation was the major underlying arrhythmia ( n  = 92, 71%). The mean age was 65 ± 10 years. Eighty-four patients (65%) were diagnosed with ST-elevation myocardial infarction and 108 patients (84%) had 3-vessel coronary artery disease. Forty-three cases (33%) underwent percutaneous transluminal angioplasty. The median time to CABG was 4 (range 0.2-4) h. Complete revascularization was achieved in 106 patients (83%). The stroke rate was 9% ( n  = 11) and hypoxic brain damage occurred in 16 patients (12%). Nine subjects (7%) needed extracorporeal life support. Four intraoperative deaths (3%) occurred; the 30-day mortality rate was 23% ( n  = 30); the mortality rate during follow-up was 30% ( n  = 27). A total of 79% ( n  = 70) of patients discharged alive showed good neurological outcome according to the cerebral performance category scale. CONCLUSIONS Despite the reluctance to expose patients with CA to early CABG, our data indicate that the operative strategy may not be as unfavourable as suspected.

Accuracy of Cardiac Output by Nine Different Pulse Contour Algorithms in Cardiac Surgery Patients: A Comparison with Transpulmonary Thermodilution.

Objective. Today, there exist several different pulse contour algorithms for calculation of cardiac output (CO). The aim of the present study was to compare the accuracy of nine different pulse contour algorithms with transpulmonary thermodilution before and after cardiopulmonary bypass (CPB). Methods. Thirty patients scheduled for elective coronary surgery were studied before and after CPB. A passive leg raising maneuver was also performed. Measurements included CO obtained by transpulmonary thermodilution (COTPTD) and by nine pulse contour algorithms (COX1–9). Calibration of pulse contour algorithms was performed by esophageal Doppler ultrasound after induction of anesthesia and 15 min after CPB. Correlations, Bland-Altman analysis, four-quadrant, and polar analysis were also calculated. Results. There was only a poor correlation between COTPTD and COX1–9 during passive leg raising and in the period before and after CPB. Percentage error exceeded the required 30% limit. Four-quadrant and polar analysis revealed poor trending ability for most algorithms before and after CPB. The Liljestrand-Zander algorithm revealed the best reliability. Conclusions. Estimation of CO by nine different pulse contour algorithms revealed poor accuracy compared with transpulmonary thermodilution. Furthermore, the less-invasive algorithms showed an insufficient capability for trending hemodynamic changes before and after CPB. The Liljestrand-Zander algorithm demonstrated the highest reliability. This trial is registered with NCT02438228 (ClinicalTrials.gov).

Impact of Gender on Outcome in Octogenarians after Coronary Artery Bypass Grafting

Background Increasing life expectancy makes cardiac surgery in octogenarians not very uncommon. In this study, the impact of gender on outcome of octogenarians after coronary artery bypass grafting (CABG) was assessed. Materials and Methods We retrospectively studied 485 octogenarians (176 females: mean age 82.4 ± 2.2 years vs. 306 males: mean age 82.2 ± 2.4 years) who underwent isolated CABG using extracorporeal circulation between January 2005 and December 2012. Results No significant differences were noted between both gender groups with regard to preoperative risk factors. At baseline, the groups differed significantly with respect to mean logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) (women: 22.3 ± 17.4% vs. men: 17.5 ± 13.3%; p < 0.001). Likewise, EuroSCORE II differs significantly between women and men in our cohort (women: 16.7 ± 11.9% vs. men: 13.9 ± 10.7%; p = 0.008). Intraoperatively, the number of distal anastomoses (3.1 ± 0.9 vs. 3.2 ± 0.8), the mean extracorporeal circulation time (99 ± 31 vs. 102 ± 29 minutes), and the mean aortic cross‐clamp time (63 ± 31 vs. 60 ± 19 minutes) were similar in both groups. Postoperatively, no significant differences in complications and major morbidity were observed between the groups. The 30‐day mortality (women 8.0 vs. men 9.7%; p = 0.62) were without statistical significance between the groups. Conclusion Outcome of octogenarians after CABG resulted in acceptable mortality. Female gender was not associated with increased risks for morbidity and mortality after surgery. Satisfactory outcomes encourage the offering of surgery in octogenarians.