94Course of contained annulus ruptures after TAVI: the ENCORE (European contained rupture)-registry

Background

An asymptomatic contained rupture (CR) of the aortic annulus is a rare complication of transcatheter aortic valve implantation (TAVI). Their clinical implication is unclear so far.

Purpose

To determine the long-term outcomes in patients with CR.

Methods

The ENCORE-registry is a multicenter registry (6 centers across Europe) of patients with CR diagnosed on post-TAVI computed tomography angiography (CTA) or transesophageal echocardiography (TEE).

Results

A total of 21 patients (mean age 81.9±4.1 years, 81% balloon-expandable TAVI-prostheses) were diagnosed with CR (62% located adjacent to the left coronary cusp, mean size of lesions was 15.3±6.9 x 8.5±3.3 x 8.5±2.3 mm). Seventeen were diagnosed among a total of 1602 consecutive routine post-TAVI CTA (incidence 1.1%), two in TEE and two in post-TAVI CTA (each conducted due to suspicion of periinterventional complications). During a mean follow-up of 2.3±1.7 years nine patients (43%) died from non-cardiac causes. None of the patients exhibited symptoms or underwent interventional treatment related to the CR, no sudden cardiac death occurred. A follow-up CTA, performed in eleven patients 240±176 days post-TAVI, revealed stable CR findings in seven, regression in one, and remission in three patients.

Conclusion

The results of our ENCORE-registry demonstrate a benign course of initially asymptomatic contained ruptures of the aortic annulus after TAVI supporting a watch-and-wait approach in these patients. Thus, no specific treatment seems to be necessary.

Torsade de pointes as a complication of subarachnoid hemorrhage: a critical reappraisal

Subarachnoid hemorrhage is widely accepted as a potential cause of torsade de pointes (TdP), yet this putative etiologic relationship has never been systematically evaluated. We therefore undertook a MEDLINE search from 1966 through 1993, with relevant back referencing, and identified 20 cases of TdP in the setting of subarachnoid hemorrhage. It was impossible in any of these cases (usually because of insufficient data) to completely exclude one or more alternative explanations for TdP, including congenital long QT syndrome, hypokalemia, hypomagnesemia, or drug-induced QT prolongation. Furthermore, of a total of 1,139 patients in 16 prospective series of subarachnoid hemorrhage with electrographic analyses, there were only five reported cases of TdP, all in patients with hypokalemia. Thus, extremely limited scientific data exist to support the notion that subarachnoid hemorrhage can be a distinct cause of TdP. Until more definitive evidence is available, the development of TdP in patients with subarachnoid hemorrhage is probably better characterized as a multifactorial phenomenon occurring in an acute, typically intensive care, setting.

Probucol-associated tachyarrhythmic events and QT prolongation: importance of gender

From published articles and adverse reactions reports filed with the FDA (available through the Freedom of Information Act), we analyzed occurrences of tachyarrhythmias and the magnitude of QTc prolongation associated with probucol therapy. Of 16 cases of tachyarrhythmic events reported in association with probucol, 15 (94%) occurred in women (p < 0.01 vs expected value of 58%). Tachyarrhythmias were specifically described as TdP in 11 (63%) cases, all women; additional potential contributory QT-prolonging factors (besides probucol) were not identifiable in 2 of the 11 cases. We also analyzed QTc responses in 359 probucol-treated patients, all having baseline QTc < or = 0.44 sec1/2. At doses of 500 to 1000 mg/day, probucol-associated prolongation of QTc to values > or = 0.45 sec1/2 was observed in 22% of women versus 7% of men (p < 0.001) and to values > or = 0.47 sec1/2 in 8% of women versus 2% of men (p < 0.03). Multivariate analysis identified baseline QTc (p < 0.0001) and female gender (p < 0.03), but neither age nor dose, as significant independent predictors of QTc prolongation to > or = 0.45 sec1/2 with probucol. These findings have relevance to the clinical use of probucol, provide further evidence that women have a relatively greater predisposition to development of acquired long QT syndrome, and carry implications for the design of trials involving QT-prolonging drugs.

Increased propensity of women to develop torsades de pointes during complete heart block

INTRODUCTION

To determine whether an increased female gender susceptibility to torsades de pointes (TdP) may exist in a clinical model of bradycardia-induced long QT syndrome, we investigated reported cases of TdP associated with acquired complete heart block.

METHODS AND RESULTS

Seventy-two cases reported in the medical literature dating from 1941 through 1993 were identified, all describing TdP or "transient ventricular tachycardia/fibrillation" (to include those cases reported prior to the use of TdP terminology) in the setting of acquired complete heart block unassociated with QT prolonging drugs. Expected female prevalence in complete heart block was estimated at 52%, based on projections derived from 206,016 hospital discharges in the National Inpatient Profile (Commission on Professional and Hospital Activities, Ann Arbor, MI), over the years 1985 through 1992. During complete heart block, mean heart rate was 37 beats/min in both sexes (combined n = 43), and absolute QT interval ranged from 0.52 to 0.88 seconds, with a mean of 0.68 seconds (n = 25). Female prevalence among patients with TdP during complete heart block was greater than expected: 72% for all studied cases (P < 0.001); 70% (P < 0.04) and 74% (P < 0.02) among those reported prior to (n = 35) and during or after (n = 37) 1980, respectively; 73% (P < 0.03) among those with documented normokalemia (n = 26); and 68% (P = 0.2) among those with a prolonged QT interval and known polymorphic VT (i.e., unequivocal TdP; n = 25).

CONCLUSION

Despite inherent limitations of this retrospective study, the data are consistent in suggesting a greater than expected female prevalence among patients with TdP related to complete heart block. This finding lends support to a broadening concept of increased susceptibility of women to the development of TdP in various settings of QT prolongation.