Long-term monitoring of respiratory rate in patients with heart failure: the Multiparametric Heart Failure Evaluation in Implantable Cardioverter-Defibrillator Patients (MULTITUDE-HF) study.

BACKGROUND: Monitoring respiratory rate (RR) is recommended at the time of hospital presentation for acute decompensation in heart failure (HF). Device-based continuous monitoring of RR may be helpful for diagnostic and prognostic stratification after implantable cardioverter-defibrillator (ICD) implantation. This study was undertaken to analyze short- and long-term changes in ICD-measured RR and to relate RR with the patient's clinical status and the occurrence of HF events. METHODS: One hundred twenty-four consecutive HF patients who received ICD endowed with this diagnostic capability (Boston Scientific Inc., Natick, MA, USA) were prospectively enrolled. Patients were followed up for 12 months. RESULTS: At the baseline, the proportion of New York Heart Association (NYHA) class III-IV was higher among patients with daily maximum RR >27 breaths/min (third tertile) than those with <24 breaths/min (first tertile) (43 vs. 23%, p < 0.05). Moreover, the ejection fraction was lower (27 ± 7 vs. 34 ± 8%, p < 0.05). In patients with HF hospitalizations (33 events) and urgent visits for HF (15 events), the weekly average of RR calculated over the 7 days preceding hospital accesses did not differ from values recorded at the baseline and before scheduled follow-up visits. However, the weekly variation in RR (i.e., the difference between maximum and minimum values collected over the week) was significantly higher prior to hospitalization (p < 0.05). A weekly variation >3 breaths/min in maximum RR predicted an impending hospital admission for HF with sensitivity of 73 % and specificity of 57%. CONCLUSIONS: In this study, elevated values of ICD-monitored RR identified patients with worse functional status and lower systolic function. The weekly variation in RR increased before HF exacerbation. This monitoring technology may represent a useful tool in the clinical management of patients with HF.

Incidence and predictors of heart failure hospitalization and death in permanent pacemaker patients: a single-centre experience over medium-term follow-up.

AIM: The aim of this study was to assess the incidence and clinical predictors of the development of new-onset heart failure (HF) over medium-term follow-up, in patients treated with permanent pacing in daily clinical practice. METHODS AND RESULTS: We retrospectively enrolled all consecutive patients who underwent single- or dual-chamber pacemaker implantation at the study centre. Patients with a left ventricular ejection fraction (LVEF) ≤35% or a prior diagnosis of HF were excluded. Ventricular leads were routinely implanted in the right apex. Pacemakers were implanted in 490 patients with a standard pacemaker indication and LVEF >35%. Left bundle-branch block (LBBB) was reported in 30 (8%) patients, and an LVEF <50% in 64 (13%) patients. During a follow-up of 27 ± 21 months, 32 (7%) patients reached the combined endpoint of HF death or hospitalization. On multivariate analysis, LBBB (HR, 3.50; 95% CI, 1.1-11.1; P = 0.033) and LVEF <50% (HR, 5.1; 95% CI, 1.9-14.2; P = 0.002) were confirmed as independent predictors of HF death or hospitalization. Patients with LVEF <50% and/or LBBB displayed significantly higher rates of HF death or hospitalization (log-rank test, all P<0.001). CONCLUSION: The majority of patients with a standard indication for permanent pacing and normal LV function remained in a clinically stable condition after pacemaker implantation. However, ∼7% of patients developed new-onset HF over a period of follow-up of 27 months, and the presence of LBBB and LVEF <50% at the baseline predicted HF death or hospitalization.

DDD versus VVIR versus VVI mode in patients with indication to dual-chamber stimulation: a prospective, randomized, controlled, single-blind study.

BACKGROUND: The aim of this study was to compare VVI, VVIR and DDD modes in patients with indication to dual-chamber stimulation, depending on left ventricular function. METHODS: Two groups of patients were implanted with a DDD pacemaker: Group I with ejection fraction > 40% and Group II with ejection fraction < 40%. Patients with a history of atrial arrhythmia or retrograde conduction were excluded. At follow-up (1 month each) quality of life (QoL), patient preference and echo parameters were collected. At hospital discharge all patients were programmed in DDD for 1 month and then randomized to VVI or VVIR mode. At the end of the period in VVI or VVIR mode each patient underwent a control period in DDD and then was programmed in VVIR or VVI mode. RESULTS: Seventeen patients out of 23 preferred DDD mode and 6 did not perceive any subjective difference among DDD, VVI and VVIR modes (4/9 in Group I and 2/14 in Group II, p = 0.0017). QoL was significantly different between the two groups and at each follow-up showed the best values in DDD. The correlation between QoL and Tei index was 0.62 in Group I (p < 0.001) and 0.35 in Group II (p = 0.001). Neither ejection fraction nor fractional shortening showed any significant difference during the three phases of the study. CONCLUSIONS: Most patients preferred the DDD mode. The Tei index showed a good correlation with QoL and both QoL and Tei index significantly improved with DDD mode as compared to VVI and VVIR.