Possible Subclinical Leaflet Thrombosis in Bioprosthetic Aortic Valves.

BACKGROUND: A finding of reduced aortic-valve leaflet motion was noted on computed tomography (CT) in a patient who had a stroke after transcatheter aortic-valve replacement (TAVR) during an ongoing clinical trial. This finding raised a concern about possible subclinical leaflet thrombosis and prompted further investigation. METHODS: We analyzed data obtained from 55 patients in a clinical trial of TAVR and from two single-center registries that included 132 patients who were undergoing either TAVR or surgical aortic-valve bioprosthesis implantation. We obtained four-dimensional, volume-rendered CT scans along with data on anticoagulation and clinical outcomes (including strokes and transient ischemic attacks [TIAs]). RESULTS: Reduced leaflet motion was noted on CT in 22 of 55 patients (40%) in the clinical trial and in 17 of 132 patients (13%) in the two registries. Reduced leaflet motion was detected among patients with multiple bioprosthesis types, including transcatheter and surgical bioprostheses. Therapeutic anticoagulation with warfarin, as compared with dual antiplatelet therapy, was associated with a decreased incidence of reduced leaflet motion (0% and 55%, respectively, P=0.01 in the clinical trial; and 0% and 29%, respectively, P=0.04 in the pooled registries). In patients who were reevaluated with follow-up CT, restoration of leaflet motion was noted in all 11 patients who were receiving anticoagulation and in 1 of 10 patients who were not receiving anticoagulation (P<0.001). There was no significant difference in the incidence of stroke or TIA between patients with reduced leaflet motion and those with normal leaflet motion in the clinical trial (2 of 22 patients and 0 of 33 patients, respectively; P=0.16), although in the pooled registries, a significant difference was detected (3 of 17 patients and 1 of 115 patients, respectively; P=0.007). CONCLUSIONS: Reduced aortic-valve leaflet motion was shown in patients with bioprosthetic aortic valves. The condition resolved with therapeutic anticoagulation. The effect of this finding on clinical outcomes including stroke needs further investigation. (Funded by St. Jude Medical and Cedars-Sinai Heart Institute; Portico-IDE ClinicalTrials.gov number, NCT02000115; SAVORY registry, NCT02426307; and RESOLVE registry, NCT02318342.).

Systematic CT Methodology for the Evaluation of Subclinical Leaflet Thrombosis.

Subclinical leaflet thrombosis was recently described in a randomized trial of transcatheter aortic valve replacement. It was subsequently demonstrated in a series of registries that this was a commonly observed imaging finding seen in all transcatheter and surgical bioprostheses. The phenomenon has aroused considerable interest due to the as-yet-undefined risk for later clinical events and the possibility of pharmacological intervention with anticoagulation. Subclinical leaflet thrombosis is easily detected noninvasively by technically suitable computed tomography (CT) with a high degree of concordance to transesophageal echocardiography findings. The CT hallmarks were noted to be hypoattenuated leaflet thickening (HALT) associated with reduced leaflet motion (RELM). The combination of HALT and RELM signified hypoattenuation affecting motion, the standardized imaging endpoint used. This paper describes the systematic CT evaluation methodology that was devised during the Portico trial investigation and U.S. Food and Drug Administration submission; it also highlights the need for an ongoing discussion among experts to enable, with the help of the Valve Academic Research Consortium, standardization of reporting of this imaging finding to cater to the present and future needs of clinical trials.

Linear cryoablation of the left atrium versus pulmonary vein cryoisolation in patients with permanent atrial fibrillation and valvular heart disease: correlation of electroanatomic mapping and long-term clinical results.

BACKGROUND: The aim of this study was to clarify the role of pulmonary vein isolation (PVI) alone versus left atrial linear lesions in the treatment of permanent atrial fibrillation (AF) in patients with left atrial dilatation and valvular disease. The primary end point was to assess the persistence of sinus rhythm (SR) off antiarrhythmic drugs (AADs) at 2-year follow-up and to correlate clinical outcome with surgical results validated with electroanatomic mapping (EAM). METHODS AND RESULTS: A total of 105 patients with permanent AF undergoing valve surgery were assigned to 3 different groups: in groups "U" and "7," left atrial linear cryoablation was performed, whereas in group "PV" patients, anatomic cryoisolation of pulmonary veins only was performed. In groups U and 7, SR was achieved in 57% of patients, whereas it was achieved in 20% of PV patients during 2-year follow-up. In the first 51 patients, the ablation schemes were validated with EAM. The EAM showed that the U lesion was never obtained: in 59% of these patients, a complete 7 lesion was achieved instead; in the 7 group, a complete 7 lesion was present in 65% of patients, whereas a complete PVI was obtained in 71% of patients. Considering patients in whom a complete 7 lesion was demonstrated with the EAM, SR without AADs was achieved in 86% of patients, whereas only 25% of patients with complete PVI were in SR without AADs. CONCLUSIONS: In patients with permanent AF, left atrial dilatation and valvular heart disease linear lesions in the posterior region of the left atrium are more effective than PVI alone. With cryoablation, the surgical intent is fulfilled in only approximately 65% of the cases. Knowing the real anatomic and electrophysiological effects of surgical ablation is necessary to correctly interpret the clinical outcome.

Left main coronary arterial lesion after microwave epicardial ablation.

We present a case of left main coronary arterial lesion in a 62-year-old man who had undergone mitral valve replacement and microwave epicardial ablation. On postoperative day 90, the patient had an anterior myocardial infarction. The coronary angiography displayed the diagnosis of the left main trunk lesion. A myocardial revascularization was urgently performed, the postoperative course was uneventful, and the patient was in sinus rhythm. The left atrial epicardial ablation represents the ultimate step in the surgical treatment of chronic atrial fibrillation; nevertheless, the left main trunk lesion may occur as an extremely severe complication. The incorrect placement of the microwave probe may be responsible for the development of critical coronary artery stenosis.

Cryoablation of the left posterior atrial wall: 95 patients and 3 years of mean follow-up.

OBJECTIVE: Endocardial ablation of the left atrial posterior wall has been used to treat atrial fibrillation. Aim of the study was to evaluate its efficacy looking for the ablation pattern allowing a fast execution with limited interference on atrial contractility. Moreover a statistical analysis to identify predictors of long-term sinus rhythm recovery has been provided. METHODS: From April 1998 to May 2002, 95 patients with permanent (mean duration 65 months) or persistent (33%) atrial fibrillation have undergone three different ablation patterns, only 1 patient being affected by lone atrial fibrillation. Mean antero-posterior left atrial diameter was 76.2 mm. The prospective study collected information regarding variables related to patients' demographics, disease's characteristics and type of surgical ablation employed. Dependent variables were presence of sinus rhythm either at discharge and at 6 months. A logistic regression analysis was used to estimate the association between the collected variables and sinus rhythm restoration. RESULTS: In-hospital and late mortality rate were 3.2 and 6.3% respectively. At discharge 67 patients (72.8%) were in sinus rhythm while at a mean follow-up of 3 years, 81.4% of 86 surviving patients are in sinus rhythm. Major adverse events rate including cardiac reoperation, pace-maker implantation and cerebrovascular accident were 8.5, 6.3 and 4.2%, respectively. Pre-operative atrial fibrillation duration, left atrial dimension and type of mitral disease did not show any correlation with long term success while the lesion pattern and the rhythm at discharge were significant predictive factors. Survival is significantly higher in patients who converted to sinus rhythm at discharge (P=0.014) with respect to those who remained in atrial fibrillation. CONCLUSIONS: Permanent and persistent atrial fibrillation associated to a major cardiac disease can be safely treated with a linear ablation of the left atrial posterior wall. Satisfactory results in terms of rhythm restoration may be achieved regardless of the duration of the arrhythmia and its effects on atrial diameter. Any effort should be prompted to discharge patients in sinus rhythm. Life expectancy is longer if sinus rhythm is restored.

Surgical treatment of atrial fibrillation in the beating heart: a novel approach.

Up to 50% of patients undergoing mitral valve surgery have concomitant atrial fibrillation. An epicardial approach may offer the benefit of reducing the aortic cross-clamping time and avoiding an undue left atriotomy. During the last year we have been developing a simple technique to reproduce epicardially the same lesion pattern we had previously achieved endocardially. Two patients with chronic atrial fibrillation received atrial ablation using a microwave energy probe (Flex-10, AFx Inc., Fremont, CA, USA) immediately before undergoing a concomitant cardiac procedure. The procedure is relatively quick to perform and with appropriate care can be conducted with a low risk of perioperative adverse events.

Aspergillus left ventricular assist device endocarditis.

Left ventricular assist device (LVAD) support is an established therapy for patients with end-stage heart failure as a bridge to transplant; its usage as an alternative for those patients not eligible for transplant is not an established therapy yet. A 68-year-old male had a Thoratec-Heartmate LVAD implanted as destination therapy. After an uneventful (apart from early fever) recovery in the intensive care unit, the patient developed an intractable high temperature, and generalized sepsis and died 21 days following implant. The white cell blood count never exceeded the guard limits, and the patient succumbed with severe LVAD valve malfunction. At post-mortem examination friable material consisting of fungal hyphae was found on the inflow and outflow valves. According to published clinical trials, infection accounts for more than 40% of mortality in LVAD supported patients. Fungal LVAD endocarditis is a particularly deadly disease. Successful management requires a high level of suspicion and timely institution of antifungal therapy to control the infection. This has led some authors to recommend empiric antifungal therapy in LVAD recipients with culture-negative sepsis unresponsive to broad-spectrum antibiotics.

Aortic valve-sparing operations in patients with aneurysms of the aortic root or ascending aorta: preliminary results.

OBJECTIVE: Aortic valve-sparing operations were developed to preserve the native aortic valve in patients with aneurysms of the aortic root or ascending aorta and normal aortic valve leaflets. This paper describes our initial experience with valve-sparing operations and early clinical and echocardiographic results obtained. METHODS: From October 2002 to March 2004, 32 consecutive patients underwent aortic valve-sparing operations at the Istituto Clinico Humanitas, Rozzano, Italy. Preoperative transesophageal echocardiography showed moderate or severe aortic incompetence (AI) in 15 patients (47%). Twenty-nine patients underwent reimplantation of the aortic valve and 3 patients remodeling of one sinus. In 2 cases prolapsing cusp repair was carried out. RESULTS: There were no intraoperative deaths. At discharge, two-dimensional echocardiogram showed no or trivial aortic incompetence (AI) in 17 (52%) patients and mild AI in 13 (42%); 2 (6%) patients had severe AI requiring reoperation, respectively 4 and 6 weeks later. CONCLUSIONS: The valve-sparing procedures showed good preliminary results, thus encouraging further use of this type of repair. However, further larger studies and long-term results are needed in order to define the durability of these techniques.

Aortic root replacement with the Carboseal composite valve graft: analysis of risk factors.

This retrospective analysis of a selected series of Bentall-De Bono procedures was carried out in order to evaluate the performance of the Carboseal composite valve graft (Sulzer Carbomedics Inc, Austin, TX, USA). Between October 1997 and April 2004, 120 patients underwent aortic root replacement with the Carboseal Composite Valve Graft. The mean age of patients was 59.7+/-13.4 years (range, 21-83 years); 96 patients (80%) were male. Eighty-nine patients (74.2%) had annulaortic ectasia, 10 patients (8.3%) post-stenotic dilatation, 3 (2.5%) post dissection aneurysm, 2 (1.7%) acute type A dissection and 1 (0.8%) endocarditis. The average follow-up duration was 29.2 months (range 2-82 months). Hospital mortality was 1.7% (2 of 120 patients). The actuarial survival rate (including hospital mortality) was 97.2+/-1.5% at 1 year, 91.6+/-3.5% at 3 years and 84.0+/-8.0% at 5 years. Chronic renal failure was an independent risk factor for late mortality (P=0.02). The actuarial freedom from pseudoaneurysms at 3 years was higher among patients without Marfan syndrome (94.7+/-3.2% vs. 75.0+/-21.6% at 3 years, P<0.003). In our recent series, the Bentall-De Bono operation provided good results with low incidence of prosthetic related complications. Pseudoaneurysms requiring re-operation have a higher incidence among patients with Marfan syndrome.

A video-assisted thoracoscopic technique to encircle the four pulmonary veins: a new surgical intervention for atrial fibrillation ablation.

BACKGROUND: Atrial fibrillation (AF) is the most common of the so-called benign arrhythmias. It affects not only life expectancy but also quality of life. Until recently, surgeons have most often encountered AF in association with ischemic or valvular disease but rarely as lone atrial fibrillation (LAF). For the subset of LAF patients, a minimally invasive procedure is recommended. METHODS: Using an animal model, we have developed a video-assisted thoracoscopic approach to atrial ablation whereby the ablation is performed encircling the four pulmonary veins as through a median sternotomy. RESULTS: Fifteen animals were used, and in 5 a complete encircling of the pulmonary veins was accomplished using the thoracoscopic approach. DISCUSSION: Video-assisted thoracoscopy is a feasible and safe approach for epicardial pulmonary vein ablation. This technique offers the option of surgery to a class of patients who are resistant to medical therapy but for whom the presence of LAF contraindicates the open chest approach.