Johannes Blumenstein

Human minimally invasive off-pump valve-in-a-valve implantation.

Reoperative heart valve replacement for degenerated xenografts is associated with an increased surgical risk. We used our experience with transcatheter transapical aortic valve implantation to perform a transapical off-pump aortic valve-in-a-valve implantation. Hemodynamic function was excellent and the patient had a fast and uneventful recovery.

Transapical Aortic Valve Implantation

Background— Transapical aortic valve implantation has evolved to a reproducible therapeutic option for high-risk patients. The aim of the present study was to evaluate our learning experience over 4 years and to analyze outcome-related risk factors. Methods and Results— A total of 299 patients who received transapical aortic valve implantation between February 2006 and January 2010 with the Edwards SAPIEN transcatheter prosthesis were analyzed according to early experience (EE; patients 1 to 150) and recent experience (RE; patients 151 to 299). Patients consistently demonstrated high risk scores, and major perioperative parameters were comparable between the 2 groups. RE patients had a significantly higher logistic EuroSCORE (RE 33.2±17.2, EE 29.4±14; P=0.039) but a significantly lower STS (Society of Thoracic Surgeons) score (RE 11.4±7.5, EE 13.5±7.8; P=0.019). Use of contrast dye (EE 104±78 mL, RE 93±46 mL) and the need to perform a balloon redilation were significantly reduced in the RE group. Thirty-day mortality decreased from 11.3% to 6.0%, and 1-year mortality improved significantly from 30.7% (EE) to 21.5% in the RE patients (P=0.047). Multivariate logistic regression analysis revealed reduced vital capacity (<70%) and concomitant preoperative mitral regurgitation >1+ as the only independent predictors of 30-day mortality. Classic variables such as age, logistic EuroSCORE >30%, and STS score >15% failed to predict mortality. Conclusions— Recent results with transapical aortic valve implantation indicate a progressive improvement in outcomes despite an unchanged patient risk profile, which reflects a significant learning curve that includes a better understanding of optimal patient selection. Classic surgical risk factors fail to predict outcome, which indicates the need for new transapical aortic valve implantation–specific risk scores.

Risk of acute kidney injury after minimally invasive transapical aortic valve implantation in 270 patients

OBJECTIVE Contrast agent is a potential risk factor for acute kidney injury (AKI). Little is known about the incidence of contrast-induced nephropathy (CIN) after trans-apical aortic valve implantation (TA-AVI) and on the impact of contrast exposure during preoperative computed tomography (CT) scan and cardiac catheterization. METHODS A total of 270 consecutive high-risk patients received TA-AVI for symptomatic aortic valve stenosis during a 3-year period. Different preoperative, peri-procedural, and postoperative variables were analyzed by uni- and multivariate logistic regression concerning incidence of early (<7 days) AKI and need for renal replacement therapy (RRT). Nine patients on chronic preoperative dialysis were excluded. RESULTS Mean age was 82 ± 5.8 years, 71% were female. LogEuroSCORE (European System for Cardiac Operative Risk Evaluation) and STS Score were 31.4 ± 15.6% and 12.1 ± 7.4%, respectively. Preoperative estimated glomerular filtration rate (eGFR) <60 ml min(-1) was present in 35.2%. CT scan and cardiac catheterization within 7 days before TA-AVI were performed in 43.7% and 20.3% of the patients and were associated with a mean contrast-agent exposition of 110 ± 21 ml for CT scans and 91 ± 65 ml for cardiac catheterization. Regarding the postoperative renal outcome, an improved or at least stable eGFR was seen in more than 50% of the patients. Intra-operative contrast-agent application was 99 ± 64 ml and correlated significantly to the development of postoperative AKI and need for RRT (p=0.013 and p=0.003). Postoperative RRT was required in 15.7%. Chronic renal insufficiency (odds ratio (OR)=6.8, p=0.025) and number of blood transfusions (OR=8.8, p=0.009) were independent risk factors for RRT. Postoperative AKI occurred in 16.1% and intra-operative contrast-agent burden >99 ml (OR=2.3, p=0.038), new thrombocytopenia (OR=4.4, p=0.005) and pathological leucocyte count (OR=2.8, p=0.009) were independent risk factors for this event. Early (within 1-7 days before TA-AVI) preoperative CT and cardiac catheterization did not significantly increase incidence of RRT or AKI. Short-term and long-term survival was explicitly lower in the AKI and in the RRT groups (p<0.001 each). CONCLUSIONS GFR improves after TA-AVI. Postoperative AKI and RRT depend on the amount of intra-operative contrast agent. These results strongly support the need for intra-operative tools to reduce contrast-agent exposition during TA-AVI.

Minimally invasive off-pump valve-in-a-ring implantation: the atrial transcatheter approach for re-operative mitral valve replacement after failed repair.

OBJECTIVE Based upon recent developments in transcatheter technology, this study was designed to evaluate the feasibility and haemodynamic performance of transcatheter valve-in-a-ring (VinR) implantation for potentially failed mitral repair using a minimally invasive, transatrial, off-pump approach. METHODS Adult sheep (54.3+/-3.0 kg) underwent mitral valve repair with a 26 mm complete annuloplasty ring (Physio) using standard conventional techniques. To simulate the redo operation, a transcatheter 23 mm pericardial prosthesis (Edwards Sapien) mounted on a balloon-inflatable steel stent was deployed within the annuloplasty ring. VinR implantation was performed off-pump under rapid pacing in four and on-pump in three animals using an antegrade transatrial approach under fluoroscopic guidance. RESULTS Transcatheter VinR implantation was successful in all seven sheep. Mean transvalvular gradient was 4.9+/-0.3 mmHg. VinR function was excellent with no leak in one, good with mild leak in five (trans-stent: four, paravalvular: one) and sufficient with moderate central leak in one animal, respectively. Valve deployment required 10.0+/-0.7 min and all transcatheter prostheses were confirmed in good position on postmortem analysis, without any signs of valve dislocation or embolisation. In an in-vitro model, the minimum force required to dislodge the valve was 32.9+/-5.2N, which was well above the normal estimated forces generated by the left ventricle. One animal was kept alive to assess mid-term outcome and is still well 12 months after the VinR implantation. CONCLUSIONS Transatrial, transcatheter mitral VinR implantation is feasible using a minimally invasive off-pump approach. VinR implantation is a promising concept for re-operative surgery for selected patients after failed mitral valve repair.

Minimally invasive off-pump valve-in-a-valve implantation: the atrial transcatheter approach for re-operative mitral valve replacement

AIMS This study was designed to evaluate the feasibility and haemodynamic performance of transcatheter valve-in-a-valve (VinV) implantation for failed mitral xenografts using a minimally invasive, transatrial, off-pump approach. METHODS AND RESULTS Nine adult sheep (71.1 +/- 3.4 kg) underwent mitral valve replacement with a 25 mm bioprosthesis using standard conventional techniques. After weaning from cardiopulmonary bypass, a transcatheter 23 mm pericardial prosthesis mounted on a balloon-inflatable steel stent was deployed within the conventional xenograft. The VinV implantation (10.1 +/- 0.9 min) was performed off-pump using an antegrade transatrial approach under fluoroscopic guidance successfully in all nine sheep. Mean transvalvular gradient was 4.6 +/- 1.0 mmHg, and five of nine sheep had no paravalvular leak with two sheep each having mild and moderate one. All transcatheter prostheses were confirmed in good position on post-mortem analysis. In an in vitro model, the minimum force required to dislodge the valve was 22.5 +/- 3.0 N, which was well above the normal estimated forces generated by the left ventricle (LV). When this model was attached to a LV assist device, the VinV withstood pressure loops of 300 mmHg, without dislocation or embolization. CONCLUSION Transatrial, transcatheter mitral VinV implantation is feasible off pump. This is a truly minimally invasive concept to treat patients with failed xenografts using a right lateral minithoracotomy.

Transfemoral Aortic Valve Implantation of Edwards SAPIEN XT Without Predilatation Is Feasible

Transcatheter aortic valve implantation (TAVI) without predilatation has fewer procedural steps and thereby potentially fewer complications. This has been demonstrated for the antegrade transapical access; however, whether TAVI can be safely performed without predilatation using the retrograde transfemoral route is unknown.

Extracorporeal life support in cardiovascular patients with observed refractory in-hospital cardiac arrest is associated with favourable short and long-term outcomes: A propensity-matched analysis.

Aims: Extracorporeal life support (ECLS) has shown encouraging survival rates in patients with in-hospital cardiac arrest; however, its routine use is still controversial. We compared the survival of patients with in-hospital cardiac arrest receiving conventional cardiopulmonary resuscitation (CCPR) to that of patients with ECLS as an adjunct to cardiopulmonary resuscitation (ECPR). Methods: A total of 353 patients with in-hospital cardiac arrest (272 CCPR and 52 ECPR) were included in this retrospective, propensity score-adjusted (1:1 matched), single-centre study. Primary endpoints were survival at 30 days, long-term survival and neurological outcome defined by the cerebral performance categories score. Results: In the unmatched groups patients undergoing ECPR initially had significantly higher APACHE II scores (P=0.03), increased norepinephrine dosages (P=0.03) and elevated levels of creatine kinase (P<0.0001), creatinine (P=0.04) and lactate (P=0.02) before cardiopulmonary resuscitation compared with those undergoing CCPR. After equalising these parameters significant differences were observed in short and long-term survival, favouring ECPR over CCPR (27% vs. 17%; P=0.01 (short-term) and 23.1% vs. 11.5%; P=0.008 (long-term); median follow-up duration after discharge 1136 days (interquartile range 823–1416)). There was no significant difference in the incidence of a cerebral performance categories score of 1 or 2 between the matched groups (CCPR 66.7% vs. ECPR 83.3%; P=0.77). ECLS implantation was the only significant and independent predictor of mortality in multivariate Cox regression analysis (hazard ratio 0.57, 95% confidence interval 0.35–0.90; P=0.02). Conclusion: In our cohort of cardiovascular patients ECPR was associated with better short- and long-term survival over CCPR, with a good neurological outcome in the majority of the patients with refractory in-hospital cardiac arrest.

Contemporary management of aortic stenosis: surgical aortic valve replacement remains the gold standard

Aortic valve disease is the most frequent acquired heart valve lesion in humans. In western communities, approximately 90% of patients present with aortic stenosis (AS), predominantly of a calcific degenerative aetiology. The remaining approximately 10% of patients predominantly present with aortic valve incompetence.

Neutrophil gelatinase-associated lipocalin (NGAL) for the early detection of cardiac surgery associated acute kidney injury

Abstract Background. Acute kidney injury (AKI) is a common complication after cardiac surgery. Neutrophil gelatinase-associated lipocalin (NGAL) may be an early biomarker for cardiac surgery–associated (CSA) AKI. We investigated whether increased urinary NGAL concentrations were predictive of AKI within 4 days after surgery and of mortality within 9 months. Methods. Consecutive patients (n = 141) undergoing major cardiac surgery were included. Creatinine, blood urea nitrogen, cystatin C and urinary NGAL were measured before, 4 hours and 4 days after extracorporeal circulation. Results. AKI was observed in 47 (33.3%) patients. The 4-hour urinary NGAL measurement was an independent predictor of stage 2 and 3 AKI (AUC 0.901; 95% CI 0.81–0.99). Patients with AKI had a higher 9-month mortality rate (19.1% vs. 3.2%; logrank 10.9; P = 0.001; HR 19.8; 95% CI 3.7–107.1). Urinary NGAL was not predictive of mortality within 9 months after surgery. Conclusion. Urinary NGAL is a biomarker for very early risk stratification of AKI after cardiac surgery and may be useful as a basis for early interventional strategies to prevent CSA-AKI.

Trends in aortic valve replacement in Germany in 2015: transcatheter versus isolated surgical aortic valve repair

AimsWe analysed the number of procedures, indications, and in-hospital mortality rates of all patients undergoing isolated surgical aortic valve replacement (sAVR) or transvascular (TV-) and transapical (TA-) transcatheter aortic valve implantation (TAVI) from 2012 to 2015 in Germany.Methods and resultsMore than 31,000 aortic valve procedures were performed in 2015 in Germany, representing a total increase of 4.5% over 2014. TV-TAVI accounts for 13,108 of these procedures, with an increase of 21%, whereas the numbers of isolated sAVR and TA-TAVI decreased slightly. Age, frailty, high risk, and patients’ choice were the main reasons for a catheter-based intervention. In 2015, the in-hospital mortality rate after TV-TAVI decreased to 3.4%, approaching that of sAVR (2.9%), despite a considerably higher baseline risk. A stratified analysis according to the German aortic valve (AKL) score demonstrated a further decrease of the in-hospital mortality for TV-TAVI, showing a lower in-hospital mortality rate than expected in all risk groups. Importantly, this also accounts for the lowest risk group with an AKL score <3% showing an in-hospital mortality rate of 1.7%, which is now comparable to that of sAVR (1.5%). In all other risk groups, the in-hospital mortality in patients undergoing TV-TAVI was lower than in patients undergoing sAVR.ConclusionsMortality after TV-TAVI keeps decreasing over the last years and equals that of SAVR in the lowest risk cohort in the meanwhile. All TV-TAVI patients have significantly lower observed than expected mortality, which will further lead to a redefinition of standard of care.