Transcatheter Aortic Valve Thrombosis: Incidence, Predisposing Factors, and Clinical Implications.

BACKGROUND: There are limited data on the incidence, clinical implications, and predisposing factors of transcatheter heart valve (THV) thrombosis following transcatheter aortic valve replacement (TAVR). OBJECTIVES: The authors assessed the incidence, potential predictors, and clinical implications of THV thrombosis as determined by contrast-enhanced multidetector computed tomography (MDCT) after TAVR. METHODS: Among 460 consecutive patients who underwent TAVR with the Edwards Sapien XT or Sapien 3 (Edwards Lifesciences, Irvine, California) THV, 405 (88%) underwent MDCT in addition to transthoracic and transesophageal echocardiography 1 to 3 months post-TAVR. MDCT scans were evaluated for hypoattenuated leaflet thickening that indicated THV thrombosis. RESULTS: MDCT verified THV thrombosis in 28 of 405 (7%) patients. A total of 23 patients had subclinical THV thrombosis, whereas 5 (18%) patients experienced clinically overt obstructive THV thrombosis. THV thrombosis risk did not differ among different generations of THVs (8% vs. 6%; p = 0.42). The risk of THV thrombosis in patients who did not receive warfarin was higher compared with patients who received warfarin (10.7% vs. 1.8%; risk ratio [RR]: 6.09; 95% confidence interval [CI]: 1.86 to 19.84). A larger THV was associated with an increased risk of THV thrombosis (p = 0.03). In multivariable analysis, a 29-mm THV (RR: 2.89; 95% CI: 1.44 to 5.80) and no post-TAVR warfarin treatment (RR: 5.46; 95% CI: 1.68 to 17.7) independently predicted THV thrombosis. Treatment with warfarin effectively reverted THV thrombosis and normalized THV function in 85% of patients as documented by follow-up transesophageal echocardiography and MDCT. CONCLUSIONS: Incidence of THV thrombosis in this large study was 7%. A larger THV size may predispose to THV thrombosis, whereas treatment with warfarin appears to have a protective effect. Although often subclinical, THV thrombosis may have important clinical implications.

Three-dimensional multidetector computed tomography versus conventional 2-dimensional transesophageal echocardiography for annular sizing in transcatheter aortic valve replacement: Influence on postprocedural paravalvular aortic regurgitation.

OBJECTIVES: In transcatheter aortic valve replacement (TAVR), the influence of aortic annular assessment with either multidetector computed tomography (MDCT) or conventional transesophageal echocardiography (TEE) on the incidence of postprocedural paravalvular aortic regurgitation (PAR) was evaluated. BACKGROUND: PAR remains a major limitation in TAVR. Appropriate selection of transcatheter heart valve (THV) size is crucial to prevent PAR. METHODS: Outcomes following TAVR with a balloon-expandable THV were compared in two retrospective cohorts identified according to whether THV size selection was based on TEE (study group 1, n = 80) or MDCT (study group 2, n = 58). RESULTS: The two study groups were comparable with regard to baseline clinical, risk score, and echocardiographic characteristics. The incidence of moderate/severe PAR was lower in study group 2 than in group 1, 8.6% versus 28.8% (P < 0.01). The difference between the THV nominal diameter and MDCT annular diameter was predictive of moderate/severe PAR (AUC 0.84; 95% CI: 0.72-0.92). Neither age, gender, body mass index, annular eccentricity index, aortic valve calcification nor the difference between the THV diameter and the TEE annular diameter predicted postprocedural PAR. Increased THV oversizing relative to the MDCT mean annular diameter was associated with reduced severity of PAR. No difference in perprocedural complications between two study groups was observed. CONCLUSION: MDCT-based annular sizing in TAVR significantly reduces postprocedural PAR, and THV oversizing appears pivotal in this aspect. Further delineation of the optimal degree of THV oversizing is needed.

A prospective, randomised trial of transapical transcatheter aortic valve implantation vs. surgical aortic valve replacement in operable elderly patients with aortic stenosis: the STACCATO trial.

AIMS: In a prospective randomised trial we aimed to compare transapical transcatheter aortic valve implantation (a-TAVI) with surgical aortic valve replacement (SAVR) in operable elderly patients. METHODS AND RESULTS: The study was designed as a randomised controlled trial of a-TAVI (Edwards SAPIEN heart valve system; Edwards Lifesciences, Irvine, CA, USA) vs. SAVR. Operable patients with isolated aortic valve stenosis and an age ≥75 years were included. The primary endpoint was the composite of all-cause mortality, cerebral stroke and/or renal failure requiring haemodialysis at 30 days. After advice from the Data Safety Monitoring Board, the study was prematurely terminated after the inclusion of 70 patients because of an excess of events in the a-TAVI group. The primary endpoint was met in five a-TAVI patients (two deaths, two strokes, and one case of renal failure requiring dialysis) vs. one stroke in the SAVR group (p=0.07). In the a-TAVI group, one patient was converted to SAVR because of an abnormally positioned heart, and four patients were re-operated with open heart surgery because of annulus rupture (n=1), severe paravalvular leakage (n=2), and blockage of the left coronary artery (n=1). In the SAVR group, one patient was converted to TAVI because of a large intra-thoracic goitre. CONCLUSIONS: Given the limitations of a small prematurely terminated study, our results suggest that a-TAVI in its present form may be associated with complications and device success rates in low-risk patients similar or even inferior to those found in high-risk patients with aortic valve stenosis. This will probably change in the near future with improved catheter based devices and better pre-procedural assessment.

Pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension. Ten years experience in Denmark.

OBJECTIVES: To evaluate survival and functional outcome in patients treated by pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension in Denmark. DESIGN: Follow-up of the first 50 patients operated at Aarhus University Hospital, Denmark. RESULTS: Fifty patients underwent PEA in the period from 1994 to mid 2004. Prior to surgery all patients were in World Health Organization (WHO) function class III (n=33) or IV (n=17). The mean pulmonary artery pressure was 50 mmHg (range 25-76), cardiac index 1.8 l min(-1)m(-2) (range 0.8-2.8) and pulmonary vascular resistance 819 dyn s cm(-5) (range 241-3,067). In-hospital mortality was 12/50 (24%). Surgical mortality was highest in the early period. Since year 2000 in-hospital deaths occurred in only 2 among 23 patients (9%). Leading causes of death were persistent pulmonary hypertension and bleeding. Three patients died during long-term follow-up with a median observation time of 3 years. The overall 5 year survival rate was 74%. At 3 months follow-up 90% of the patients (34/38) had improved one or more WHO functional classes and the systolic pulmonary artery pressure estimated by Doppler echocardiography had decreased from 80 mmHg (range 49-115) to 43 mmHg (range 14-95). CONCLUSION: Pulmonary endarterectomy has been successfully implemented in Denmark. The perioperative mortality was reduced over time to 9% during the past 5 years. Functional outcome and long-term survival were excellent stressing the importance of surgical treatment for chronic thromboembolic pulmonary hypertension.