Subcutaneous implantable cardiac defibrillators: indications and limitations.

The implantable cardioverter defibrillator is today an indisputable evidence-based treatment for cardiac sudden death both in primary and secondary prevention. However, trans-venous cardioverter defibrillator implantation still carries a not negligible risk of complications both acutely and during follow-up. Trans-venous endocardial lead is the weak link of implantable cardioverter defibrillator (ICD) technology being the source of most mechanical complications on vessels and heart structures and exposed to infection, malfunction and recalls. A totally subcutaneous defibrillation lead has recently been introduced in clinical practice. With the subcutaneous pulse generator forms a defibrillation system that leaves the vessels and the heart completely "untouched." Subcutaneous ICD has proven to be safe and effective in many clinical trials. Patients without pacing indications and at higher risk of complications from trans-venous lead implantation represent the perfect candidates to S-ICD technology. However, with technical improvement, it is reasonable to expect a further expansion of indications.

Plasma N-terminal protype-B natriuretic peptide levels in risk assessment of patients with mitral regurgitation secondary to ischemic and nonischemic dilated cardiomyopathy.

BACKGROUND: Functional mitral regurgitation (MR) is a factor affecting prognosis of patients with chronic left ventricular (LV) dysfunction. The aim of the study was to investigate whether the evaluation of plasma N-terminal protype-B natriuretic peptide (NT-proBNP) concentrations is useful for prognostic assessment of patients with functional MR due to either ischemic or nonischemic chronic LV dysfunction. METHODS: Echocardiograms were obtained in 207 patients with chronic LV dysfunction (ejection fraction or=0.7 cm raised MR grade to severe. Median follow-up duration was 29 months. RESULTS: The NT-proBNP levels increased significantly with MR severity. At multivariate analysis, NT-proBNP was an independent predictor of cardiac death (hazard ratio 2.17, CI 1.10-4.30, P = .026) and the most powerful predictor of cardiac death or heart failure-related hospitalization (hazard ratio 3.19, CI 1.89-5.37, P < .0001). A progressively worse outcome was apparent when patients were stratified by a graded increase in MR severity and by quartiles of NT-proBNP levels. Increased NT-proBNP concentrations and more-than-mild MR identified patients with the highest risk of cardiac mortality. CONCLUSION: Assessment of plasma NT-proBNP allows for stratifying patients with functional MR regardless of their degree of valvular incompetence. Even in case of only mild or moderate MR, but increased NT-proBNP, patients have to face poor outcome.

Prognostic value of N-terminal pro-type-B natriuretic peptide and Doppler left ventricular diastolic variables in patients with chronic systolic heart failure stabilized by therapy.

Prognostication of patients with chronic heart failure (HF) stabilized by therapy may be difficult. Therefore, the aim was to evaluate whether combined assessment of plasma N-terminal pro-B natriuretic peptide (NT-pro-BNP) and Doppler left ventricular (LV) diastolic variables was relevant to the prognosis of patients with stable HF. Outpatients with LV systolic HF (ejection fraction < or =45%), classified using clinical criteria as decompensated (n = 94) and stable HF (n = 219), underwent a complete Doppler echocardiographic study. NT-pro-BNP was measured together with mitral wave velocities, E wave deceleration time, and tissue Doppler early septal annular velocity. Median follow-up was 22 months. Freedom from all-cause mortality or HF hospitalization at 24 months was worst (44%) in patients with decompensated HF, intermediate (58%) in patients with stable HF with NT-pro-BNP higher than the median (>1,129 pg/ml), and best (92%) in patients with lower NT-pro-BNP (log-rank p <0.0001). In patients with stable HF, NT-pro-BNP >1,129 pg/ml (hazard ratio [HR] 2.84, p = 0.003), E wave deceleration time <150 ms (HR 2.31, p = 0.004), and tissue Doppler early septal annular velocity <8 cm/s (HR 2.18, p = 0.01) were predictors of the end point at multivariate analysis. The addition of Doppler LV diastolic variables and NT-pro-BNP significantly improved the chi-square test for outcome prediction (from 14.4 to 46.4). In conclusion, NT-pro-BNP and spectral and tissue Doppler variables of LV diastolic dysfunction added independent and incremental contributions to prognostic stratification of patients with stable HF.

Prognostic significance of tricuspid annular motion and plasma NT-proBNP in patients with heart failure and moderate-to-severe functional mitral regurgitation.

BACKGROUND: The role of the right ventricle has been relatively neglected proportionate to its importance. We sought to evaluate the impact of right ventricular (RV) and NT-proBNP on the outcome of patients with heart failure (HF) and functional mitral regurgitation (MR). METHODS AND PATIENTS: Outpatients with left ventricular (LV) systolic HF (ejection fraction [EF] < or =45%) and moderate-to-severe MR measured by a vena contracta width > or =0.5 cm were prospectively enrolled (n=142). Indexes of LV and RV function, including tricuspid annular plane systolic excursion (TAPSE), RV fractional area change and tissue Doppler RV acceleration at isovolumic contraction and NT-proBNP plasma levels were measured at the time of the index echocardiogram. RESULTS: Multivariate predictors of all-cause mortality included TAPSE<16 mm (hazards ratio [HR]: 2.64; p=0.009) and plasma NT-proBNP> or =3283 pg/ml (HR: 2.58; p=0.011). TAPSE<16 mm and plasma NT-proBNP> or =3283 pg/ml added incremental prognostic information to LV EF< or =25%, NYHA classes 3-4, coronary artery disease, elderly age and male sex. The 36-month Kaplan-Meier curve showed that survival was worst in the group with TAPSE<16 mm and NT-proBNP> or =3283 pg/ml (p<0.0001). CONCLUSION: This study demonstrates the significance of TAPSE and plasma NT-proBNP in predicting all-cause mortality in patients with systolic HF and moderate-to-severe functional MR.

Right ventricular dysfunction is a major predictor of outcome in patients with moderate to severe mitral regurgitation and left ventricular dysfunction.

BACKGROUND: This study aimed to assess the prognostic value of right ventricular (RV) dysfunction in patients with secondary mitral regurgitation (MR) by simple methods of echocardiographic measurement. Although both RV dysfunction and functional MR may affect prognosis of patients with heart failure (HF) due to left ventricular (LV) dysfunction, information is lacking regarding the impact of RV dysfunction in patients with functional MR. METHODS: Among 356 consecutive patients with chronic HF due to LV dysfunction (ejection fraction < or = 45%), 107 met the entry criteria of moderate to severe MR as assessed by a vena contracta width > or = 0.5 cm. Tricuspid annular plane systolic excursion (TAPSE) was acquired to evaluate RV function. Median follow-up duration was 21 months. RESULTS: Among patients with a vena contracta width > or = 0.5 cm, 30 (28%) died and 28 (26%) were hospitalized for worsening HF. By multivariate analysis, TAPSE < or = 14 mm (hazard ratio [HR] 2.83, P = .027) and LV ejection fraction (HR 2.17, P = .099) were predictive of death from all causes. Independent predictors of freedom from all-cause mortality or hospitalization for worsening HF were New York Heart Association class (HR 2.15, P = .027), age (HR 1.98, P = .021) and TAPSE < or = 14 mm (HR 1.96, P = .031). At 24 months, survival was 45% in those with the worse TAPSE, whereas it was 82% in those with TAPSE > 14 mm (log-rank statistic = 0.0002). Aminoterminal pro-type B natriuretic peptide plasma levels were higher in patients with vena contracta width of > or = 0.5 cm and TAPSE < or = 14 mm. CONCLUSIONS: This study shows that RV function, assessed by TAPSE, plays a major role in the outcome of patients with functional moderate to severe MR.

N-terminal protype-B natriuretic peptide and Doppler diastolic variables are incremental for risk stratification of patients with NYHA class I-II systolic heart failure.

BACKGROUND: In systolic heart failure (HF), preventing the development of severe symptoms, before patients are in advanced NYHA functional classes, is a worthwhile target of therapy. Early recognition of left ventricular (LV) diastolic dysfunction and neuroendocrine activation may have an important impact on patient's outcome. AIM: To investigate whether N-terminal proBNP (NT-proBNP) and mitral flow and tissue Doppler (TD) diastolic parameters are incremental for risk stratification of systolic HF patients in NYHA class I and II. METHODS: The study consisted of 232 consecutive outpatients with systolic HF (ejection fraction [EF] 544 pg/ml (hazards ratio [HR]: 2.66; p=0.012), EF <37% (HR: 2.45; p=0.006), E