Roman Lehmann

Complex sleep apnoea in congestive heart failure

Background Sleep disordered breathing is common and of prognostic significance in patients with congestive heart failure (CHF). Complex sleep apnoea (complexSA) is defined as the emergence of central sleep apnoea during continuous positive airway pressure (CPAP) treatment in patients with obstructive sleep apnoea (OSA). This study aims to determine the prevalence and predictors for complexSA in patients with CHF with OSA, and to assess the effects of treatment with adaptive servoventilation. Methods 192 patients with CHF (left ventricular ejection fraction (LVEF) ≤45%, New York Heart Association (NYHA) class ≥2) and OSA (apnoea–hypopnoea index (AHI) ≥15) were investigated using echocardiography, cardiopulmonary exercise testing, measurement of hyperoxic, hypercapnic ventilatory response, 6 min walk test and measurement of N-terminal pro-brain natriuretic peptide (NT-proBNP) prior to CPAP introduction. If patients demonstrated complexSA (AHI >15/h with <10% obstructive events) during CPAP titration, adaptive servoventilation was introduced and the investigations were repeated at 3 monthly follow-up visits. Results ComplexSA developed in 34 patients (18%) during CPAP titration. After adjustment for demographic and cardiac parameters, measures of CO2 sensitivity (higher hyperoxic, hypercapnic ventilatory response) were independently associated with complexSA. Patients using adaptive servoventilation had improved AHI, NYHA class, NT-proBNP concentration, LVEF, hyperoxic, hypercapnic ventilatory response, oxygen uptake during cardiopulmonary exercise testing and the relationship between minute ventilation and the rate of CO2 elimination (VE/Vco2 slope) at last individual follow-up (14±4 months). Conclusion There is a high prevalence of complexSA in patients with OSA and CHF, and those who develop complexSA have evidence of higher respiratory controller gain before application of CPAP. Treatment with adaptive servoventilation effectively suppressed complexSA and had positive effects on cardiac function and respiratory stability.

Myocardial fibrosis severity on cardiac magnetic resonance imaging predicts sustained arrhythmic events in hypertrophic cardiomyopathy.

BACKGROUND The purpose of our study was to correlate the incidence of adequate implantable cardioverter-defibrillator (ICD) interventions in hypertrophic cardiomyopathy (HCM) patients with risk markers (RMs) for sudden cardiac death (SCD) plus myocardial fibrosis as detected by late gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) imaging. METHODS In all, 87 patients with HCM underwent LGE-CMR imaging prior to ICD implantation, performed for secondary (n = 2; 2%) or primary SCD prophylaxis (n = 85; 98%). Fibrosis was graded with a 17-segment left ventricular model (0 = absent, 1 = point-shaped, 2 = limited to 1 left ventricular segment, 3 = involving ≥ 2 segments). During follow-up, ICD memories were read out by a physician blinded to the individual patient data. RESULTS The number of RMs per patient was 1.9 ± 0.8. Myocardial fibrosis was present in 78 patients (90%); 26 (30%) had a fibrosis score of 3. During follow-up (3.5 ± 2.6 [range, 0.2-11.4 years]), 15 patients had 50 appropriate ICD interventions. Episodes of atrial fibrillation were found in 28 patients. Fibrosis severity correlated with occurrence of ventricular tachycardia (Cramérs V, or φc = 0.4, P < 0.001) and atrial fibrillation (φc = 0.6, P < 0.001). On multivariate regression analysis, an independent association between myocardial fibrosis (ß = 0.6, P < 0.01) and sustained ventricular tachycardia was found. CONCLUSIONS In HCM patients treated with ICD implantation because of a high SCD risk by traditional RM assessment, a high rate of arrhythmic events was observed during long-term follow-up. In a cohort of patients with clinical markers for high risk of SCD, severity of myocardial fibrosis as detected by an easy LGE-CMR scoring system was associated with future arrhythmic events and appropriate ICD therapies.

Echocardiographic Particle Image Velocimetry for the Evaluation of Diastolic Function in Hypertrophic Nonobstructive Cardiomyopathy

To use particle image velocimetry (PIV) echocardiography for the evaluation of diastolic dysfunction (DD) in patients with hypertrophic nonobstructive cardiomyopathy (HNCM).

Respiratory Effects of Adaptive Servoventilation Therapy in Patients with Heart Failure and Cheyne-Stokes Respiration Compared to Healthy Volunteers

Background: Nocturnal adaptive servoventilation (ASV) therapy is now frequently used to treat Cheyne-Stokes respiration (CSR), which is highly prevalent in patients with moderate-to-severe heart failure (HF) and characterized by periodical breathing (hyperventilation). Objectives: This study analyzed and compared the acute effects of a novel ASV device on carbon dioxide pressure (pCO2) and oxygen saturation (SaO2) in HF patients with CSR and healthy volunteers. The influence of being asleep or awake on the ASV algorithm was also determined. Methods: All subjects underwent ASV (PaceWave™, ResMed) for 1 h. Transcutaneous pCO2 (PtcCO2) and SaO2 were assessed transcutaneously, while wakefulness was analyzed using EEG recordings. Assessments were made 30 min before and after ASV, and during 1 h of ASV. Results: Twenty HF patients (19 male; age 79 ± 12 years) and 15 volunteers (13 male, age 25 ± 4 years) were included. When awake, ASV was associated with a trend towards a decrease in PtcCO2 and an increase in SaO2 versus baseline in HF patients (34.4 ± 3.2 to 33.7 ± 3.8 mm Hg and 93.8 ± 2.6 to 94.9 ± 2.6%, respectively) and volunteers (39.5 ± 3.0 to 38.2 ± 3.8 mm Hg and 96.9 ± 1.3 to 97.8 ± 0.9%). While asleep during ASV, PtcCO2 increased to 36.3 ± 3.8 mm Hg and SaO2 decreased to 93.8 ± 2.6% in HF patients, with similar changes in volunteers (PtcCO2 41.7 ± 3.0 mm Hg, SaO2 97.1 ± 1.2). All comparisons were statistically significant (p ≤ 0.05, except the PtcCO2 decrease in both groups when awake). Conclusions: ASV therapy might result in hyperventilation when subjects are awake, but while asleep, PtcCO2 increased to mid-normal values, effects that would be favorable in HF patients with CSR.

Left Ventricular Dyssynchrony Predicts Clinical Response to CRT – A Long-Term Follow-Up Single-Center Prospective Observational Cohort Study

Until now, there is no consensus regarding the definition of a clinical response to cardiac resynchronization therapy (CRT) in patients with chronic heart failure (CHF) and systolic left ventricular (LV) dysfunction. The aim of this study was to evaluate if echocardiography is predictive for an objective improvement in exercise capacity during long‐term follow‐up of CRT.

Rethinking cardiac resynchronization therapy: The impact of ventricular dyssynchrony on outcome

OBJECTIVE To analyze whether left ventricular dyssynchrony (LVD) at baseline is predictive for long-term outcome in heart failure (CHF) patients with left ventricular (LV) dysfunction and conduction disturbances treated with cardiac resynchronization therapy (CRT). METHODS In 535 consecutive individuals with CHF scheduled for implantation of a CRT device, LVD was assessed by tissue Doppler imaging (TDI), defined as an electromechanical delay (EMD) difference of ≥40 ms in 2 opposed left ventricular wall regions (septal vs. lateral, anterior vs. inferior). All-cause mortality, heart transplantation, or assist device implantation was defined as combined primary end point. Secondary end points were measures of reverse LV remodeling and of symptomatic improvement. RESULTS Mean follow-up was 68 ± 36 [range: 4-150] months. LVD at baseline was present in 308 patients (61%). Of these, 24% reached the combined primary endpoint in contrast to 58% of patients without LVD (p < 0.001). Furthermore, patients with LVD showed pronounced improvement of all secondary end point parameters. In our cohort LVD was an independent predictor for outcome (hazard ratio [95% CI]: 0.30 [0.21-0.42], p < 0.001). CONCLUSIONS LVD at baseline as assessed by TDI is associated with a more pronounced clinical improvement and is a predictor for transplant-free long-term survival in CRT recipients.