Predictors of a high defibrillation threshold test during routine ICD implantation

BACKGROUND

There is growing evidence that routine defibrillation threshold (DFT) testing during implantable cardioverter defibrillator (ICD) implantation is not necessary. However a small group of patients might be at risk if no DFT testing is performed.

METHODS

Patients with a new pectoral ICD implantation in our hospital between 2006 and 2014 were included in a retrospective registry. A clinical high DFT was defined as a safety margin <10 J of the maximal device output. Logistic regression for prediction of high DFT was performed using patient characteristics, clinical, echocardiographic and device-related parameters.

RESULTS

DFT testing was performed in 788/864 (91.2%) procedures. In 76 (8.8%) patients no DFT testing was performed mainly due to atrial fibrillation, intra-cardiac thrombus, hemodynamic instability or logistical reasons. A high DFT was present in 44 (5.6%) patients. A QRS duration ≥150 ms, a low left ventricular ejection fraction (LVEF ≤25%), a severely dilated left ventricle ≥60 mm and right sided pre-pectoral implantations were univariate predictors of a high DFT. Independent predictors of a high DFT were a LVEF ≤25% (HR 2.195, 95%CI 1.085-4.443) and right sided pre-pectoral implantations (HR 3.135, 95% CI 1.186-8.287).

CONCLUSIONS

A high DFT is still present in about 5% of patients and is more frequent in patients with a severely dilated left ventricle, a very low LVEF, right sided pre-pectoral implantation and wider QRS duration. It might be clinically important to continue DFT testing in these high risk patients.

Prognostic significance of improvement in right ventricular systolic function during cardiac resynchronization therapy

Objectives There is conflicting evidence concerning the role of right ventricular (RV) systolic dysfunction in the long-term clinical outcome after cardiac resynchronization therapy (CRT). Therefore we aimed to assess evolution of RV systolic function during CRT, covariates associated with its improvement, and its impact on outcome. Methods and results All CRT device implantations (Jan 2009-Dec 2011) in our institution were reviewed. Records of 69 patients (25% female, mean age 62.8 ± 9.2 years, mean left ventricular (LV) ejection fraction 27 ± 8%) were analyzed. Baseline RV fractional area change (FAC) < 35% was present in 37 patients (54%). At one year, 24 of them (65%) improved in RV FAC. LV remodeling and mitral regurgitation were significantly associated with the likelihood of RV FAC improvement (OR 4.80, 95% CI 1.13-20.46, P = 0.034 and OR 0.32, 95% CI 0.12-0.89, P = 0.029, respectively). The composite endpoint of death or heart transplantation occurred in 23 patients (33%) over a mean follow-up of 2.8 ± 1.4 years. RV FAC at one year (HR 0.90, 95% CI 0.86-0.94, P < .001) was, independently of NYHA class and LV remodeling, associated with clinical outcome. Conclusions RV systolic function might improve during CRT. This seems mainly due to changed left-sided hemodynamics and LV remodeling. Good RV systolic function is independently related with better outcome.

Cancer After Heart Transplantation: A 25-year Single-center Perspective

BACKGROUND

Cancer is a major cause of morbidity and mortality after heart transplantation.

METHODS

We studied 541 heart transplant patients from a single center over a period of 25 years, with a mean follow-up of 10.7 years. We determined incidence, type, risk factors, and prognosis for cancer after heart transplantation.

RESULTS

Cancer was diagnosed in 181 patients, at a mean of 7.7 years after transplantation. Cumulative incidence of cancer at 5, 10, and 20 years was 14%, 29%, and 60%, respectively. The most frequent cancers were spinocellular skin cancer (22%), basocellular skin cancer (19%), lung cancer (16%), lymphoma (11%) and prostate cancer (10%). Age at transplantation > 50 years (hazard ratio, 2.9; P < .001) and male recipient gender (hazard ratio, 1.7; P = .038) were significant risk factors for posttransplant malignancy on multivariate Cox proportional hazards analysis. Median patient survival after diagnosis of cancer was 2.9 years for patients with noncutaneous cancer, versus 13.1 years for patients with only skin cancer (P < .001).

Inhibition of plasmin activity by sulfated polyvinylalcohol-acrylate copolymers

The effect of four sulfated polyvinylalcohol-acrylate copolymers and heparin on plasminogen activation and on plasmin activity is studied. The molecules differing in charge (proportion of negatively charged units 40.5%-73.5% of the total) and in size (5600 Da-8800 Da) accelerate plasminogen activation by 2- up to 4-fold at a 7-fold molar excess of the polyvinylacrylates over plasminogen. They, however, exert a concentration and charge-dependent effect on plasmin: both the amidolytic (half-maximal effect at a 1.33-3.66 molar excess of the polyvinylacrylates) and fibrinolytic (half-maximal effect at 1.23-1.72 molar excess of the polyvinylacrylates) activities of plasmin are inhibited. In contrast, heparin (a similarly carboxylated and sulfated polymer) and polyvinylacrylates with a low number of sulfate groups (30% sulfated monomers) at concentrations up to 2.2 microM do not affect plasminogen activation and plasmin activity in a milieu of physiological ionic strength. Experiments with plasmin derivatives lacking N-terminal peptides of different length (des-kringle(1-4) and des-kringle(1-5) plasmin) show identical changes in the protease activities, precluding involvement of the kringle-domain in the interaction with the polyvinylacrylates. Fluorescence studies evidence the charge-dependent binding of the polyvinylacrylates to plasmin, but not to plasminogen. Thus, through non-covalent interaction with the protease-domain of plasmin the polyvinylacrylates inhibit fibrinolysis. Since these sulfated copolymers inhibit both thrombin [4] and plasmin activity, they may be a useful therapeutic tool in situations when both the blood coagulation and the fibrinolytic system are activated (such as intravascular coagulation and fibrinolysis, ICF).

[The role of plastic shock absorbers in dental implantation]

The mechanical behaviour of different plastics (PE, PP, PI, PA, ABS, POM) was examined by static and dynamic loading. Detection of microdeformations and photoelastic stress analysis served as the examination method. According to the results, polyethylene is unsuitable, however the other plastics, with clauses, are suitable as shock absorbers. Apart from the mechanical investigation photoelastic stress analysis also revealed the benefit of osseointegration in force transmission to the bone.

Comparative studies on the efficacy of sulphachlorpyrazine and toltrazuril for the treatment of caecal coccidiosis in chickens

The therapeutic efficacy of sulphachlorpyrazine and toltrazuril against experimentally induced Eimeria tenella infection was compared in battery and floor pen raised broiler chickens. In the battery studies, both drugs prevented coccidiosis-related mortality and decrease of weight gain to a similar degree, but toltrazuril was more effective in reducing intestinal lesions and faecal scores, when treatments were initiated 24 h postinfection. When medication was delayed until 72 h after inoculation, the sulphonamide proved to be more effective in preventing reduction of weight gain and intestinal lesions caused by the parasites. Under simulated use conditions both drugs showed an appropriate anticoccidial efficacy without major differences between them.