Maciej Dabrowski

Comparison of different quantification methods of late gadolinium enhancement in patients with hypertrophic cardiomyopathy

AIM There is no consensus regarding the technique of quantification of late gadolinium enhancement (LGE). The aim of the study was to compare different methods of LGE quantification in patients with hypertrophic cardiomyopathy (HCM). METHODS Cardiac magnetic resonance was performed in 33 patients with HCM. First, LGE was quantified by visual assessment by the team of experienced readers and compared with different thresholding techniques: from 1SD to 6SD above mean signal intensity (SI) of remote myocardium, above 50% of maximal SI of the enhanced area (full-width at half maximum, FWHM) and above peak SI of remote myocardium. RESULTS LGE was present in 25 (78%) of patients. The median mass of LGE varied greatly depending on the quantification method used and was highest with the utilization of 1SD threshold [75.5 g, interquartile range (IQR): 63.3-112.3g] and lowest for FWHM method (8.4 g, IQR: 4.3-13.3g). There was no difference in mass of LGE as assessed with 6SD threshold and FWHM when compared to visual assessment (p=0.19 and p=0.1, respectively); all other thresholding techniques provided significant differences in the median LGE size when compared to visual analysis. Results for all thresholds, except FWHM were significantly correlated with visual assessment with the strongest correlation for 6SD (rho=0.956, p<0.0001). CONCLUSIONS LGE quantification with the use of a threshold of 6SD above the mean SI of the remote myocardium provided the best agreement with visual assessment in patients with HCM.

Long term exercise capacity in patients with hypertrophic cardiomyopathy treated with percutaneous transluminal septal myocardial ablation

In hypertrophic obstructive cardiomyopathy, percutaneous transluminal septal myocardial ablation (PTSMA) improves functional capacity in the short term. However, long term functional capacity is unknown.

The value of cardiac magnetic resonance and distribution of late gadolinium enhancement for risk stratification of sudden cardiac death in patients with hypertrophic cardiomyopathy

BACKGROUND The presence of late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM) is associated with worse clinical outcome and the extent of LGE predicts the increased risk of sudden cardiac death (SCD). Limited data exist regarding the distribution of LGE. We attempted to verify whether the presence of LGE outside the interventricular insertion points carries additional risk for patients with HCM. METHODS In this prospective study, 328 patients with HCM, who underwent cardiac magnetic resonance (CMR) were enrolled. Five major risk factors for SCD were assessed in all patients. The median follow-up was 37 months. RESULTS LGE was detected in 226 (68.9%) patients. In 70 (21.3%) patients it was present only at the interventricular insertion points - LGE (+) group, while in 156 (47.6%) it was noted in other locations - LGE (++) group. Primary endpoint defined as SCD or appropriate implantable cardioverter-defibrillator intervention occurred in 14 (4.3%) patients, one in LGE (+) and 13 in LGE (++). In multivariable analysis including five traditional risk factors and left ventricular ejection fraction <50%, only the presence of LGE outside the insertion points was a significant predictor of SCD/aborted SCD (HR 10.01, 95% CI 1.21-83.86, p=0.033). The performance of the multivariable sudden cardiac death risk model was improved by the addition of LGE (++) to the traditional risk factors (likelihood ratio p=0.005). The Kaplan-Meier curves showed better event-free survival in the LGE (-) and LGE (+) patient groups compared to the LGE (++) group. CONCLUSIONS In HCM patients, presence of LGE outside interventricular insertion points is associated with increased risk of sudden cardiac death or its equivalent as well as overall mortality. Cardiac fibrosis as a substrate for SCD in HCM may be identified on CMR and serve as an imaging biomarker of increased risk.

Second transcatheter aortic valve implantation for treatment of suboptimal function of previously implanted prosthesis: review of the literature.

OBJECTIVES To systematically review reported cases of second transcatheter aortic valve deployment within a previously implanted prosthesis (TAV-in-TAV). BACKGROUND TAV-in-TAV deployment is one of the rescue strategies undertaken due to an unsuccessful or suboptimal transcatheter aortic valve implantation (TAVI) result. Currently, there are no clear indications for second valve implantation and outcomes of patients with 2 prostheses deployed remain poorly known. METHODS The MEDLINE and PubMed databases were searched for cases of TAV-in-TAV implantations of aortic valve. RESULTS Forty-three articles reporting on TAV-in-TAV deployment were included in the review. The most frequently observed indication for second valve implantation was aortic regurgitation (AR) occurring shortly after TAVI. There was a strong dominance of paravalvular over intravalvular AR, with prosthesis malposition being the main underlying cause of TAVI failure (81% of all identified cases). Perioperative echocardiographic images are crucial in identifying causes of failure and helpful in optimal rescue strategy selection. Success rate of TAV-in-TAV implantation varies from 90% to 100% with mortality rate of 0-14.3% at 30 days. Despite similar aortic valve function in follow-up, TAV-in-TAV may be an independent predictor of increased cardiovascular mortality. CONCLUSIONS TAV-in-TAV implantation is feasible and results in favorable short- and mid-term outcomes in patients with acute failure of TAVI without recourse to open-heart surgery. Further studies are needed to establish algorithm of the management of unsuccessful or suboptimal implantation results.

Clinical and echocardiographic parameters as risk factors for atrial fibrillation in patients with hypertrophic cardiomyopathy

Atrial fibrillation (AF) is a common complication in patients with hypertrophic cardiomyopathy (HCM) and may contribute to high cardiovascular morbidity and mortality. Therefore, it is important to assess parameters associated with AF in HCM patients.