Samir Ahad

Transcatheter Aortic Valve Replacement: Does Kidney Function Affect Outcome?

BACKGROUND Chronic kidney disease is a significant risk factor for mortality as well as acute kidney injury in cardiac surgery. The impact of contrast agent application on outcome is not well described in patients undergoing transcatheter aortic valve implantation. METHODS We analyzed data of 270 patients who underwent transcatheter aortic valve implantation (TAVI) between September 2008 and March 2012. Acute kidney injury was defined according to modified risk, injury, failure, loss and end-stage renal failure criteria. Patients on chronic hemodialysis were analyzed separately (n = 15). In 129 (47.8%) patients chronic kidney disease was apparent preoperatively. On average, 83.7 (± 32.4) mL of contrast agent were used per patient. RESULTS Postoperatively, 41 patients (15.2%) developed acute kidney injury. In 19 patients (7.1%) transient renal replacement therapy was necessary; no chronic hemodialysis was required. Thirty-day-mortality did not differ between patients with or without chronic kidney disease (7.0% vs 7.1%, p = 0.97). Additionally, chronic kidney disease had no influence on the incidence of postoperative acute kidney injury (12.8% vs 20.2%, p = 0.07) or postoperative hemodialysis (5.0% vs 10.5%, p = 0.08). No correlation between the amount of contrast agent applied and the incidence of acute kidney injury could be verified (p = 0.57). CONCLUSIONS Preoperative chronic kidney disease does not increase the risk of mortality and acute kidney injury after transcatheter aortic valve implantation. Acute kidney injury after TAVI is associated with an elevated risk of mortality. The amount of contrast agent applied intra-procedurally does not affect the risk of acute kidney injury.

Transapical aortic valve implantation and minimally invasive off-pump bypass surgery

Transcatheter aortic valve implantation (TAVI) has gained increasing popularity for high-risk patients with symptomatic aortic valve stenosis. A concomitant coronary artery disease leads to a complicated management and an increased perioperative risk. This case report describes the successful total arterial coronary revascularization of the left anterior descending and the left marginal branch of the circumflex artery utilizing the left internal mammary artery (LIMA) and left radial artery in off-pump technique in combination with the transapical transcatheter aortic valve implantation via minimally invasive anterolateral access in the fifth intercostal space.

Concomitant therapy: off-pump coronary revascularization and transcatheter aortic valve implantation

OBJECTIVES Significant coronary artery disease (CAD) is common among patients evaluated for transcatheter aortic valve implantation (TAVI). Only little data exist on outcome of patients undergoing concomitant off-pump coronary revascularization and TAVI. The goal of this study was to analyse the impact of concomitant off-pump revascularization on early clinical outcome and 2-year follow-up of patients undergoing TAVI. METHODS A total of 70 patients with significant CAD and aortic valve stenosis were included between January 2011 and January 2016. Decision to perform concomitant off-pump coronary revascularization and TAVI was made by the interdisciplinary heart team according to the SYNTAX score. Prospectively assigned data were analysed retrospectively and follow-up was performed up to 2 years. RESULTS Mean age was 82.2 ± 4.0 years and 43 (61.4%) patients were male. Mean logistic European system for cardiac operative risk evaluation and Society of Thoracic Surgeons European system for cardiac operative risk evaluation score were 35.9 ± 21.9% and 12.2 ± 7.9%, respectively. SYNTAX score was 29.0 ± 12.9. Access site for TAVI was transapical in 60.0% and transaortic in 40.0%. Procedural success was 94.3%. Eighty percent of the patients had none or trace paravalvular leakage after TAVI. Severe complications requiring consecutive surgical aortic valve replacement occurred in 2 patients (2.9%). The use of cardiopulmonary bypass due to haemodynamic instability or conversion to surgical aortic valve replacement was necessary in 7 patients (10.0%). Stroke occurred in 1 patient (1.4%). Re-exploration for bleeding was necessary in 6 patients (8.6%). Thirty-day mortality was 14.3%. Two-year survival was 68.4% (95% confidence interval: 55.7-81.1%). CONCLUSIONS Simultaneously performed complete off-pump coronary revascularization is a feasible and valid option in patients with significant CAD undergoing TAVI.

Feasibility and clinical outcome after minimally invasive valve-sparing aortic root replacement

Objectives This study aims to examine the feasibility and clinical course after minimally invasive David procedure compared with those via a conventional median sternotomy. Methods One hundred and ninety-two consecutive patients who underwent elective valve-sparing aortic root replacement (David procedure) with or without additional cusp repair for aortic regurgitation ( n  = 17, 8.9%), dilatation of the aortic root ( n  = 95, 49.5%) or a combination of both pathologies ( n  = 80, 41.7%) were included. Patients with systemic disorders, such as Marfans syndrome, and emergency cases were excluded. Assessment of quality of life was performed by modified Short Form Health Survey (SF-36) questionnaire. To minimize baseline differences, a matched pair analysis was conducted. Results One hundred and seventeen patients (60.9%) received a minimally invasive hemisternotomy (Group 1), 75 patients a conventional median sternotomy (39.1%, Group 2). Patients of Group 1 were significantly younger (56.5 ± 13.6 vs 64.8 ± 11.6, P  < 0.001). Understandably, concomitant cardiac procedures were more frequent in Group 2 ( n  = 7 [6.0%] vs n  = 48 [64.0%], P  < 0.001). In hospital, mortality was 0.9% in Group 1 (1/117) and 2.7% in Group 2 (2/75; P  = 0.562). Blood loss was significantly less in Group 1 (542.6 ± 441.8 vs 996.7 ± 822.6 ml, P  < 0.001). Duration of mechanical ventilation (10.2 ± 21.8 vs 26.9 ± 109.0 h, P  < 0.001) and ICU-stay (1.9 ± 3.6 vs 3.2 ± 5.6 days, P  < 0.001) were significantly shorter in the minimally invasive group, but this differences did not remain after matching. According to SF-36 questionnaire, patients in the minimally invasive group tend to have a higher quality of life. Conclusions Minimally invasive valve-sparing aortic root replacement can be done safely via an upper partial sternotomy in experienced hands even if additional cusp repair is required.

Combined David and Frozen Elephant Trunk Procedure in Acute Aortic Dissection

BACKGROUND  Valve sparing aortic root repair by reimplantation (David procedure) is an established technique in acute aortic dissection Stanford type A involving the aortic root. In DeBakey type I dissection, aortic arch replacement using the frozen elephant trunk (FET) was introduced to promote aortic remodeling of the downstream aorta. The combination of these two complex procedures represents a challenging surgical strategy and was considered too risky so far. METHODS  All patients with acute aortic dissection DeBakey type I undergoing valve sparing aortic root repair by reimplantation technique of David combined with extended aortic repair using the FET at our center between October 2009 and December 2016 were evaluated. Outcomes are compared with patients who underwent prosthetic aortic root replacement and FET for aortic dissection in the same timeframe. RESULTS  A total of 28 patients received combined David and FET procedure, while 20 patients received prosthetic aortic root replacement and FET procedure. Thirty-day mortality was 10.7% (n = 3) for the David group and 20% (n = 4) for the root replacement group (p = 0.43). Postoperative echocardiographic control revealed an excellent aortic valve function with regurgitation grade 0° or maximum grade I° and a mean gradient of 4.3 ± 2.1 mm Hg in all patients in the David group versus 7.2 ± 2.4 mm Hg in the aortic root replacement group, p = 0.003. Computed tomography angiography scan showed positive aortic remodeling in all but three patients (91.9%). Mid-term follow-up survival was 82.1% in the David group and 68.4% in the root replacement group, p = 0.28. There was no need for reintervention at the root or descending aorta. CONCLUSION  Simultaneous application of the David and FET procedure in patients with acute aortic dissection is safe and feasible in experienced hands as compared with standard aortic root replacement plus FET. The mid-term outcomes are encouraging and noninferior to conventional surgery results.

One-stage hybrid aortic repair using the frozen elephant trunk in acute DeBakey type I aortic dissection

Background The extent of emergent surgery for acute DeBakey type I aortic dissection is discussed controversial. The frozen elephant trunk (FET) technique in addition to ascending and arch repair promotes aortic remodelling in the descending aorta and thus may provide superior long-term results in terms of less secondary re-interventions and reduced mortality linked to the downstream aorta. Methods Between October 2009 and December 2016, a total of 72 patients underwent emergent hybrid aortic repair using the FET for acute DeBakey type I aortic dissection at our centre. Data were analysed from our prospectively collected database and clinical and imaging mid-term follow-up was obtained. Results Implant success was 98.6% with an overall 30-day-mortality of 15.3%. New postoperative stroke was seen in 2.8%, new spinal cord injury in 4.2%. In follow-up (mean 37.8±21.2 months) cumulative survival was 75.0% with freedom from distal reintervention in 96.7% and aortic remodelling rate in the descending aorta in 96.5%. Conclusions Hybrid aortic repair using the FET in acute DeBakey type I aortic dissection does not elevate the perioperative risk of mortality and provides excellent aortic remodelling with low distal re-intervention rate in mid-term follow-up.