Dietmar Koschyk

Acute outcomes of MitraClip therapy for mitral regurgitation in high-surgical-risk patients: emphasis on adverse valve morphology and severe left ventricular dysfunction

AIMS We sought to assess the feasibility of catheter-based mitral valve repair using the MitraClip system in high-surgical-risk patients with mitral regurgitation (MR) > or =grade 3+. METHODS AND RESULTS MitraClip therapy was performed in 51 consecutive patients [73 +/- 10 years; 34 (67%) men] with symptomatic functional [n = 35 (69%)] or organic MR [n = 16 (31%)]. Mean logistic EuroSCORE was 29 +/- 22%; Society of Thoracic Surgeons score was 15 +/- 11. Left ventricular (LV) ejection fraction was 36 +/- 17%. In 35 patients (69%), adverse mitral valve morphology and/or severe LV dysfunction were present. MitraClip implantation was successful in 49 patients (96%). Most patients [n = 34/49 (69%)] were treated with a single clip, whereas 14 patients (29%) received two clips and one patient received three clips. Mean device and fluoroscopy times were 105 +/- 65 min and 44 +/- 28 min, respectively. Procedure-related reduction in MR severity was one grade in 16 patients (31%), two grades in 24 patients (47%), and three grades in 9 patients (18%). Forty-four of the 49 successfully treated patients (90%) showed clinical improvement at discharge [NYHA functional class > or =III in 48 patients (98%) before and 16 patients (33%) after the procedure (P < 0.0001)]. There were no procedure-related major adverse events and no in-hospital mortality. CONCLUSION Mitral valve repair using the MitraClip system was shown to be feasible in patients at high surgical risk primarily determined by an adverse mitral valve morphology and/or severe LV dysfunction.

Intramural Hematoma of the Aorta

Background—Aortic intramural hematoma (IMH) is a variant of overt aortic dissection. The predictors of progression of IMH to dissection and rupture are still unknown, and strategies for management are not established. Methods and Results—A multicenter study was conducted comprising 66 patients with IMH and hospital admission ≤48 hours after onset of initial symptoms. Among these, progression to aortic dissection or rupture occurred in 30 (45%) and death occurred in 13 (20%) patients within 30 days. Late progression was noted in 14 (21%) and death in 11 (17%) patients, yielding a 1-, 2-, and 5-year survival of 76%, 73%, and 43%, respectively. In a set of 9 variables, multivariate analysis identified IMH location in the ascending aorta (type A;P =0.02) and moderately ectatic aortic diameters (49±13 mm with progression versus 57±16 mm without progression;P =0.03) as independent predictors of early progression. In type A IMH, early mortality was 8% with swift surgery versus 55% without surgery (P =0.004). The risk of late progression of IMH was independently associated with age at index diagnosis (P =0.01) and absence of &bgr;-blocker therapy during follow-up (P =0.03). Kaplan-Meier analysis confirmed improved 1-year survival of IMH with &bgr;-blocker therapy (95% versus 67% without &bgr;-blockers;P =0.004). Conclusions—Regardless of aortic diameter, IMH of the ascending aorta (type A) is at high risk for early progression, and, thus, undelayed surgical repair should be performed. Moreover, oral &bgr;-blocker therapy may improve long-term prognosis of IMH independent of anatomical location.

Radiofrequency Current Catheter Ablation of Accessory Atrioventricular Pathways in Ebstein's Anomaly

BACKGROUND In patients with Ebsteins anomaly, localization of accessory pathways (APs) may be impeded by abnormal local electrograms recorded along the atrialized right ventricle and by the presence of multiple APs. The impact of these factors on radiofrequency (RF) current catheter ablation of APs has not been evaluated yet. METHODS AND RESULTS Twenty-one patients with Ebsteins anomaly and reentrant atrioventricular tachycardias underwent electrophysiological evaluation and subsequent attempts at RF catheter ablation. Thirty-four right-sided APs were found, with 30 located along the atrialized ventricle. Local electrograms in this region were normal in 10 patients but fragmented in 11. Fragmented electrograms prevented the clear distinction between atrial and ventricular activation potentials as well as the identification of AP potentials. Right coronary artery mapping was performed in 7 patients. Abolition of all 26 APs was achieved in the 10 patients with normal local electrograms and in 6 of 11 patients with abnormal electrograms. Right coronary artery mapping allowed AP localization and ablation in 5 patients. In the 5 patients with abnormal electrograms and a total of 8 APs, 6 APs could not be ablated. Unsuccessfully treated patients received antiarrhythmic drugs. During 22 +/- 12 months of follow-up, 5 patients had clinical recurrences, including 4 who had undergone a successful RF procedure. CONCLUSIONS In patients with Ebsteins anomaly and reentrant atrioventricular tachycardias, factors likely to account for failure of RF catheter ablation include an AP located along the atrialized right ventricle and the abnormal morphology of endocardial activation potentials generated in this region.

Predictors of aneurysmal formation after surgical correction of aortic coarctation

OBJECTIVES We sought to identify the predictors of aneurysmal formation after surgical correction of aortic coarctation. BACKGROUND In 9% of patients, aneurysms develop late after corrective surgery of coarctation of the aorta, with a 36% mortality rate if left untreated. However, the predictors of postsurgical aneurysmal formation are unknown. METHODS Of 25 aortic aneurysms requiring corrective surgery 152 +/- 78 months after the initial coarctation repair, 8 were located in the ascending aorta (type A) and 17 at the site of previous repair (local type). Seventy-four patients without progression of the aortic diameter within 189 +/- 71 months after coarctation repair were used for categorical data analysis in an attempt to identify the predictors of postsurgical aneurysmal formation. RESULTS Advanced age at coarctation repair (p = 0.004) and patch graft technique (p < 0.0005) independently predicted local aneurysmal formation. Type A aneurysm was univariately associated with the presence of a bicuspid aortic valve (p = 0.02), advanced age at coarctation repair (p = 0.044) and a high preoperative peak systolic pressure gradient of 74 +/- 21 mm Hg (p = 0.041). Conversely, multivariate analysis confirmed only the presence of a bicuspid aortic valve (p = 0.015) as an independent predictor of type A aneurysm. Receiver operating characteristic curve analysis revealed that 72% of patients with a postsurgical aneurysm had an operation at age 13.5 years or more, whereas 69% with no postsurgical aneurysm had an operation at a younger age. CONCLUSIONS Use of the patch graft technique and late correction of coarctation can predict aneurysmal formation at the site of coarctation repair, although patients with a bicuspid aortic valve may be at risk for an aneurysm developing in the ascending aorta, particularly after late repair of aortic coarctation with high preoperative pressure gradients.

Intentional occlusion of the left subclavian artery during stent-graft implantation in the thoracic aorta: risk and relevance.

Purpose: To examine the clinical consequences and/or potential need for postinterventional transposition after stent-graft occlusion of the left subclavian artery (LSA). Methods: The records of 171 consecutive patients (128 men; mean age 60.2±13.2 years, range 20–83) undergoing elective stent-graft repair in the thoracic aorta were reviewed to identify intentional endograft coverage of the ostial LSA, as documented by transesophageal echocardiography and/or aortography. Patients were treated for subacute type B dissection, true aneurysm, pseudoaneurysm, or previously operated type A dissection with persistent false lumen flow in the descending aorta. Among the 171 cases, 22 (12.9%) patients were identified with stent-graft occlusion of the LSA. Results: A systolic blood pressure differential existed between the right (138.4±14.0 mmHg) and the left (101.8±21.0 mmHg; p<0.05) arms after occlusion of the LSA. No patient showed a malperfusion syndrome during postinterventional hospitalization. During a mean follow-up of 24.0±15.8 months, 15 (68.2%) patients remained completely asymptomatic, with no functional deficit or temperature differential between the arms, while 7 patients reported mild symptoms of a subclavian steal syndrome. However, no patient required any secondary surgical intervention. Conclusions: Stent-graft—induced occlusion of the ostial LSA was tolerated by all patients without chronic functional deficit. In the absence of stenotic vertebral and/or carotid arteries and with a documented intact vertebrobasilar system, prophylactic transposition of the LSA is not required prior to intentional stent-graft occlusion of the LSA.

Emergency stent-graft placement in thoracic aortic dissection and evolving rupture.

Abstract  Background: Even with rapid diagnosis and effective medical treatment mortality in type B aortic dissection with evidence of extraaortic leakage of blood remains high. Considering a mortality rate of 29% to 50% associated with emergency surgical repair, the concept of endovascular stent‐graft placement may become a life‐saving option in impending or evolving rupture by endovascular sealing of the entry tear and subsequent abortion of leakage. Methods: The concept was tested by comparing short‐term and 1‐year outcomes of 11 patients after emergency endovascular stent‐graft placement with historic‐matched control patients subjected to conventional therapy. All patients had acute type B dissection complicated by loss of blood into periaortic spaces. Results: Emergency stent‐graft placement was successful without periprocedural morbidity, aborted leakage, and ensured reconstruction of the dissected aorta; at a mean follow‐up of 15 ± 6 months no death had occurred in the stent‐graft group whereas four patients had died with conventional treatment (p < 0.05). Conclusion: With appropriate logistics and expertise, type B aortic dissection with leakage and evolving rupture may benefit from nonsurgical reconstruction of the dissected segment by endovascular stent grafts.

Noninvasive estimation of regurgitant flow rate and volume in patients with mitral regurgitation by doppler color mapping of accelerating flow field

OBJECTIVES This study was designed to examine the accuracy of proximal accelerating flow calculations in estimating regurgitant flow rate or volume in patients with different types of mitral valve disease. BACKGROUND Flow acceleration proximal to a regurgitant orifice, observed with Doppler color flow mapping, is constituted by isovelocity surfaces centered at the orifice. By conservation of mass, the flow rate through each isovelocity surface equals the flow rate through the regurgitant orifice. METHODS Forty-six adults with mitral regurgitation of angiographic grades I to IV were studied. The proximal accelerating flow rate (Q) was calculated by: Q = 2 pi r2.Vn, where pi r2 is the area of the hemisphere and Vn is the Nyquist velocity. Radius of the hemisphere (r) was measured from two-dimensional or M-mode Doppler color recording. From the M-mode color study, integration of accelerating flow rate throughout systole yielded stroke accelerating flow volume and mean flow rate. Mitral regurgitant flow rate and stroke regurgitant volume were measured by using a combination of pulsed wave Doppler and two-dimensional echocardiographic measurements of aortic forward flow and mitral inflow. RESULTS The proximal accelerating flow region was observed in 42 of 46 patients. Maximal accelerating flow measured from either two-dimensional (372 +/- 389 ml/s) or M-mode (406 +/- 421 ml/s) Doppler color study tended to overestimate the mean regurgitant flow rate (306 +/- 253 ml/s, p < 0.05). Mean Doppler accelerating flow rate correlated well with mean regurgitant flow rate (r = 0.95, p < 0.001), although there was a tendency toward slight overestimation of mean regurgitant flow by mean accelerating flow in severe mitral regurgitation. However, there was no significant difference between the mean accelerating flow rate (318 +/- 304 ml/s) and the mean regurgitant flow rate (306 +/- 253 ml/s, p = NS) for all patients. A similar relation was found between accelerating flow stroke volume (78.27 +/- 62.72 ml) and regurgitant flow stroke volume (76.06 +/- 59.76 ml) (r = 0.95, p < 0.001). The etiology of mitral regurgitation did not appear to affect the relation between accelerating flow and regurgitant flow. CONCLUSIONS Proximal accelerating flow rate calculated by the hemispheric model of the isovelocity surface was applicable and accurate in most patients with mitral regurgitation of a variety of causes. There was slight overestimation of regurgitant flow rate by accelerating flow rate when the regurgitant lesion was more severe.

How to Guide Stent-Graft Implantation in Type B Aortic Dissection? Comparison of Angiography, Transesophageal Echocardiography, and Intravascular Ultrasound

Background—Despite growing interest in stent-graft implantation for type-B aortic dissection, there are no established recommendations to prepare and perform an implantation procedure. Methods and Results—We directly compared angiography (ANGIO), transesophageal echocardiography (TEE), and intravascular ultrasound (IVUS) intraprocedually before and after placement of 48 stent grafts in 42 consecutive patients (12 women, 61±11 years of age) with acute and chronic type-B aortic dissection for both usefulness and capability to guide aortic stent-graft implantation. Both IVUS and TEE are superior to ANGIO to identify multiple entries (52 and 43 versus 34; P<0.005 each), to diagnose false-lumen slow flow after stent-graft implantation (32 and 31 versus 24; P<0.005 each) and to detect incomplete stent apposition (18 and 16 versus 8; P<0.005 each). In comparison with ANGIO, guide wire position over the entire length of the aorta was documented more frequently by TEE and IVUS (40 and 42 versus 25; P<0.001 each). In 4 patients with abdominal extension of the dissection, only IVUS was able to accurately identify the false lumen over the entire length of the diseased aorta. TEE was superior to IVUS and ANGIO in the detection of endoleaks (5 versus 0 and 1; P<0.05 each). Intraprocedural ANGIO, TEE, and IVUS had been performed without complications in all patients. Conclusions—TEE in conjunction with ANGIO appears to be advantageous and adds incremental information to safely guide stent-graft placement in type-B aortic dissection. Additional use of IVUS was found to be helpful in patients with complex anatomy and abdominal extension of the dissection.

Predictors and outcomes after transcatheter aortic valve implantation using different approaches according to the valve academic research consortium definitions

We report the results of a large single‐center study evaluating predictors and outcomes after transcatheter aortic valve implantation (TAVI) with different devices and access routes according to the Valve Academic Research Consortium (VARC).

Transapical implantation of a second-generation transcatheter heart valve in patients with noncalcified aortic regurgitation.

OBJECTIVES This study sought to report on the feasibility and early results of transcatheter aortic valve implantation employing a second-generation device in a series of patients with pure aortic regurgitation. BACKGROUND Efficacy and safety of transcatheter aortic valve implantation in patients with calcific aortic stenosis and high surgical risk has been demonstrated. However, experience with implantation for severe noncalcified aortic regurgitation has been limited due to increased risk for valve dislocation or annular rupture. METHODS Five patients (mean age: 66.6 ± 7 years) underwent transapical implantation of a JenaValve (JenaValve Technology GmbH, Munich, Germany) transcatheter heart valve for moderate to severe, noncalcified aortic regurgitation. All patients were considered high risk for surgical aortic valve replacement after evaluation by an interdisciplinary heart team (logistic EuroSCORE [European System for Cardiac Operative Risk Evaluation] range 3.1% to 38.9%). Procedural and acute clinical outcomes were analyzed. RESULTS Implantation was successful in all cases without relevant remaining aortic regurgitation or signs of stenosis in any of the patients. No major device- or procedure-related adverse events occurred and all 5 patients were alive with improved exercise tolerance at 3-month follow-up. CONCLUSIONS Noncalcified aortic regurgitation continues to be a challenging pathology for transcatheter aortic valve implantation due to the risk for insufficient anchoring of the valve stent within the aortic annulus. This report provides first evidence that the JenaValve prosthesis may be a reasonable option in these specific patients due to its unique stent design, clipping the native aortic valve leaflets, and offering promising early results.