Transcatheter aortic valve implantation: patient selection

Transcatheter aortic valve implantation (TAVI) is a disruptive technology as it satisfies a previously unmet need which is associated with a profound therapeutic benefit. In randomized clinical trials, TAVI has been shown to improve survival compared with medical treatment among patients considered not suitable candidates for surgical aortic valve replacement (SAVR), and to provide similar outcomes as SAVR in selected high-risk patients. Currently, TAVI is limited to selected elderly patients with symptomatic severe aortic stenosis. As this patient population frequently suffers from comorbid conditions, which may influence outcomes, the selection of patients to undergo TAVI underlies a complex decision process. Several clinical risk score algorithms are routinely used, although they fall short to fully appreciate the true risk among patients currently referred for TAVI. Beyond traditional risk scores, the clinical assessment by an interdisciplinary Heart Team as well as detailed imaging of the aortic valve, aortic root, descending and abdominal aorta as well as peripheral vasculature are important prerequisites to plan a successful procedure. This review will familiarize the reader with the concepts of the interdisciplinary Heart team, risk scores as well as the most important imaging algorithms suited to select appropriate TAVI patients.

Acute coronary syndrome in patients younger than 30 years--aetiologies, baseline characteristics and long-term clinical outcome

BACKGROUND

Coronary atherosclerosis begins early in life, but acute coronary syndromes in adults aged <30 years are exceptional. We aimed to investigate the rate of occurrence, clinical and angiographic characteristics, and long-term clinical outcome of acute coronary syndrome (ACS) in young patients who were referred to two Swiss hospitals.

METHODS

From 1994 to 2010, data on all patients with ACS aged <30 years were retrospectively retrieved from our database and the patients were contacted by phone or physician's visit. Baseline, lesion and procedural characteristics, and clinical outcome were compared between patients in whom an underlying atypical aetiology was found (non-ATS group; ATS: atherosclerosis) and patients in whom no such aetiology was detected (ATS group). The clinical endpoint was freedom from any major adverse cardiac event (MACE) during follow-up.

RESULTS

A total of 27 young patients with ACS aged <30 years were admitted during the study period. They accounted for 0.05% of all coronary angiograms performed. Mean patient age was 26.8 ± 3.5 years and 22 patients (81%) were men. Current smoking (81%) and dyslipidaemia (59%) were the most frequent risk factors. Typical chest pain (n = 23; 85%) and ST-segment elevation myocardial infarction (STEMI; n = 18 [67%]) were most often found. The ATS group consisted of 17 patients (63%) and the non-ATS group of 10 patients (37%). Hereditary thrombophilia was the most frequently encountered atypical aetiology (n = 4; 15%). At 5 years, mortality and MACE rate were 7% and 19%, respectively.

CONCLUSION

ACS in young patients is an uncommon condition with a variety of possible aetiologies and distinct risk factors. In-hospital and 5-year clinical outcome is satisfactory.

Transapical access closure: the TA PLUG device

OBJECTIVES

Percutaneous closure of the transapical (TA) access site for large-calibre devices is an unsolved issue. We report the first experimental data on the TA PLUG device for true-percutaneous closure following large apical access for transcatheter aortic valve implantation.

METHODS

The TA PLUG, a self-sealing full-core closure device, was implanted in an acute animal study in six pigs (60.2 ± 0.7 kg). All the pigs received 100 IU/kg of heparin. The targeted activated clotting time was left to normalize spontaneously. After accessing the left ventricular apex with a 39 French introducer, the closure plug device was delivered with a 33 French over-the-wire system under fluoroscopic guidance into the apex. Time to full haemostasis as well as rate of bleeding was recorded. Self-anchoring properties were assessed by haemodynamic push stress under adrenalin challenge. An additional feasibility study was conducted in four pigs (58.4 ± 1.1 kg) with full surgical exposure of the apex, and assessed device anchoring by pull-force measurements with 0.5 Newton (N) increments. All the animals were electively sacrified. Post-mortem analysis of the heart was performed and the renal embolic index assessed.

RESULTS

Of six apical closure devices, five were correctly inserted and fully deployed at the first attempt. One became blocked in the delivery system and was placed successfully at the second attempt. In all the animals, complete haemostasis was immediate and no leak was recorded during the 5-h observation period. Neither leak nor any device dislodgement was observed under haemodynamic push stress with repeated left ventricular peak pressure of up to 220 mmHg. In the feasibility study assessing pull-stressing, device migration occurred at a force of 3.3 ± 0.5 N corresponding to 247.5 mmHg. Post-mortem analyses confirmed full expansion of all devices at the intended target. No macroscopic damage was identified at the surrounding myocardium. The renal embolic index was zero.

CONCLUSIONS

True-percutaneous left ventricular apex closure following large access is feasible with the self-sealing TA PLUG. The device allows for immediate haemostasis and a reliable anchoring in the acute animal setting. This is the first report of a true-percutaneous closure for large-calibre transcatheter aortic valve implantation access.

Emergency transcatheter aortic valve implantation for decompensated aortic stenosis

We report the case of an 84-year-old male presenting with syncope and dynamic ST-T wave changes due to decompensated severe valvular aortic stenosis undergoing successful emergency transcatheter aortic valve implantation.

Amplatzer left atrial appendage occlusion: single center 10-year experience

OBJECTIVES

To report a 10-year single center experience with Amplatzer devices for left atrial appendage (LAA) occlusion.

BACKGROUND

Intermediate-term outcome data following LAA occlusion are scarce.

METHODS

Short- and intermediate-term outcomes of patients who underwent LAA occlusion were assessed. All procedures were performed under local aesthesia without transesophageal echocardiography. Patients were discharged on acetylsalicylic acid and clopidogrel for 1-6 months.

RESULTS

LAA occlusion was attempted in 152 patients (105 males, age 72 ± 10 years, CHA2 DS2 -Vasc-score 3.4 ± 1.7, HAS-BLED-score 2.4 ± 1.2). Nondedicated devices were used in 32 patients (21%, ND group) and dedicated Amplatzer Cardiac Plugs were used in 120 patients (79%, ACP group). A patent foramen ovale or atrial septal defect was used for left atrial access and closed at the end of LAA occlusion in 40 patients. The short-term safety endpoints (procedural complications, bleeds) occurred in 15 (9.8%) and the efficacy endpoints (death, stroke, systemic embolization) in 0 patients. Device embolization occurred more frequently in the ND as compared to the ACP group (5 patients or 12% vs. 2 patients or 2%). Mean intermediate-term follow up of the study population was 32 months (range 1-120). Late deaths occurred in 15 patients (5 cardiovascular, 7 noncardiac, 3 unexplained). Neurologic events occurred in 2, peripheral embolism in 1, and major bleeding in 4 patients. The composite efficacy and safety endpoint occurred in 7% and 12% of patients.

CONCLUSION

LAA closure may be a good alternative to oral anticoagulation. This hypothesis needs to be tested in a randomized clinical trial to ensure that all potential biases of this observational study are accounted for.

Atrial fibrillation and aortic stenosis: impact on clinical outcomes among patients undergoing transcatheter aortic valve implantation

BACKGROUND

Atrial fibrillation (AF) is an important risk factor for stroke and is common among elderly patients undergoing transcatheter aortic valve implantation. The aim of this study was to assess the impact of AF on clinical outcomes among patients undergoing transcatheter aortic valve implantation.

METHODS AND RESULTS

Between August 2007 and October 2011, a total of 389 high-risk patients undergoing transcatheter aortic valve implantation were included into a prospective registry. AF was recorded in 131 patients (33.7%) with a mean CHA(2)DS(2)-VASC score of 4.5±1.2 and was paroxysmal in 26 (25.0%), persistent in 8 (7.7%), and permanent in 70 patients (67.3%). Patients with and without AF had similar baseline characteristics except for fewer revascularization procedures (coronary artery bypass grafting: 12% versus 22%; P=0.03) among AF patients. At 1 year, all-cause mortality was higher among patients with AF (30.9%) compared with those without AF (13.9%; hazard ratio [HR], 2.36; 95% confidence interval [CI], 1.43-3.90; P=0.0008). This was observed irrespective of the type of AF (permanent, HR, 2.47; 95% CI, 1.40-4.38; persistent, HR, 3.60; 95% CI, 1.10-11.78; paroxysmal, HR, 2.88; 95% CI, 1.37-6.05). Mortality gradually increased with higher CHA(2)DS(2)-VASC scores (score 1-3: HR, 2.20; 95% CI, 0.92-5.27; score 6-8: HR, 4.12; 95% CI, 2.07-8.20). The risks of stroke (3.9% versus 5.1%; HR, 0.76; 95% CI, 0.23-1.96; P=0.47) and life-threatening bleeding (19.8% versus 14.7%; HR, 1.37; 95% CI, 0.86-2.19; P=0.19) were similar among patients with and without AF.

CONCLUSIONS

AF is common among high-risk patients with severe aortic stenosis undergoing transcatheter aortic valve implantation and is associated with a >2-fold increased risk of all-cause and cardiovascular mortality, irrespective of the type of AF. The gradient of risk directly correlates with the CHA(2)DS(2)-VASC score.

Predictors of Clinical Outcomes in Patients With Severe Aortic Stenosis Undergoing TAVI

Background—

Patients with severe aortic stenosis at increased surgical risk continue to experience compromised long-term survival despite successful transcatheter aortic valve implantation. We used time-related pathways in a multistate analysis to identify predictors of adverse long-term outcome in patients who underwent transcatheter aortic valve implantation.

Methods and Results—

In a cohort of 389 patients with a mean age of 82.4±5.8 years and a STS score of 6.8±5.3 undergoing transcatheter aortic valve implantation between 2007 and 2011, multistate analysis was used to estimate mortality and stroke taking into account intercurrent events including kidney injury and the composite of access site and bleeding complications (ABC). Transapical access emerged as a predictor of kidney injury (hazard ratio [HR], 2.12; 95% confidence interval [CI] 1.00–4.47) and ABC (HR, 1.78; 95% CI, 1.07–2.96), but had no impact on the risk of stroke or death. Body mass index ≤20 kg/m 2 increased the risk of stroke or death (HR, 2.64; 95% CI, 1.25–5.54). Age >80 years (HR, 3.15; 95% CI, 1.11–8.92), body mass index ≤20 kg/m 2 (HR, 4.11; 95% CI, 1.33–12.70), prior stroke (HR, 16.42; 95% CI, 3.63–74.21), and presence of atrial fibrillation at baseline (HR, 4.12; 95% CI, 1.87–9.97) increased the risk of stroke and death after an intercurrent event of ABC.

Conclusions—

A body mass index ≤20 kg/m 2 was identified as a primary predictor of stroke and death after transcatheter aortic valve implantation during long-term follow-up, whereas transapical access emerged as a predictor of kidney injury and ABC. Age >80 years, body mass index ≤20 kg/m 2 , prior stroke, and presence of atrial fibrillation at baseline increased the risk of stroke and death after an intercurrent event of ABC.