Clinical symptoms of limited exercise capacity linked to AAI-DDD functionality: An in silico and in vivo approach.

BACKGROUND: Exercise capacity is an important aspect of quality of life in patients undergoing pacemaker implantation. Device algorithms for ventricular pacing avoidance have been developed to avoid unnecessary and potentially harmful effects of right ventricular pacing. However, little data exists on the immediate response of these algorithms to sudden AV block during exercise. METHODS: The ventricular pacing avoidance algorithms of four pacemaker manufacturers were tested in an ex-vivo model. The RSIM-1500-USB Device-Interactive Heart Simulator (Rivertek Medical Systems, Inc.) was used to simulate three different scenarios: the first one starting with an initially conducted atrial pacing rate of 60 min-1 , the second one starting with an atrial rate of 120 min-1 and finally a scenario starting with an atrial rate of 150 min-1 . In all three scenarios, the initially conducted atrial rate was followed by a sudden, long lasting episode of third-degree AV-block. The response to those scenarios was recorded for each of the (brand-specific) ventricular pacing avoidance algorithms. RESULTS: In the first scenario, the simulation resulted in a ventricular pause of 1333 ms (Boston Scientific), 2000 ms (Medtronic and Microport), and 2340 ms (Biotronik). In the second and third scenario, different results were observed across devices. All simulations of the second and third scenario resulted in repetitive 2:1 block response (during eight cycles) in Boston Scientific and Biotronik devices. These scenarios were confirmed in patient cases. CONCLUSION: Simulator based observations of unanticipated pacemaker-induced 2:1 block response during exercise may explain clinical symptoms experienced by some patients having a two-chamber pacemaker.

Impact of routine use of a cerebral protection device on the TAVR procedure and its short-term outcomes: a single-centre experience.

BACKGROUND: Stroke is a major concern in transcatheter aortic valve replacement (TAVR). The introduction of a cerebral protection devices may counteract the evolution towards minimally invasive TAVR. At this time, there is insufficient data to support the routine use of these devices. METHODS: We aimed to evaluate the outcome of the routine use of the Sentinel Cerebral protection system® (CPS) in patients undergoing TAVR, after completing a CT-based screening process for feasibility of Sentinel implantation. We report our initial experience with the routine implementation of the Sentinel CPS in all anatomically suitable patients undergoing TAVR. We retrospectively compared the procedural characteristics and outcomes between all TAVR patients treated with (n = 78) and without (n = 79) intended Sentinel. RESULTS: The Sentinel CPS could successfully be deployed in 99% of intended cases after CT feasibility screening. TAVR procedures with Sentinel CPS were not longer than procedures without Sentinel use (89 ± 20 versus 120 ± 50 min, p = 0.007). Sentinel CPS use was not associated with an increased risk of procedural complications. Stroke was observed in none (0%) of the Sentinel CPS patients, and in 6.3% of the non-Sentinel CPS patients (p = 0.05). The finding of stroke was associated with a high risk of early postprocedural mortality: 60% of stroke patients died within 3 months. CONCLUSION: Routine use of the Sentinel CPS in CT-screened TAVR patients is feasible with high procedural success, without significant adverse events and without counteracting the evolution towards minimally invasive TAVR. Clinically relevant stroke was observed in none of the Sentinel CPS patients.

Hemodynamic Response to Acute Volume Load and Endomyocardial NO-synthase Gene Expression in Heart Transplant Recipients.

A pulmonary capillary wedge pressure (PCWP) >18 mm Hg following volume load has been proposed as a partition value for the detection of heart failure with preserved ejection fraction. As hemodynamic changes in filling pressures (FP) have been attributed to a nitric oxide (NO)-mediated rightward shift of the pressure-volume relationship, we investigated the hemodynamic response to volume load in heart transplant recipients (HTx) and examined the role of inducible NO synthase (iNOS) gene expression on diastolic function changes. Methods: In 36 HTx, FPs were measured before and after volume load, following which Starling curves were constructed using PCWP and cardiac index (CI). Patients were categorized into those with normal (group A, n = 21) and abnormal hemodynamics (group B, n = 15, PCWP >15 mm Hg at rest or >18 mm Hg following volume load). For the establishment of the potential role of NO, endomyocardial iNOS gene expression level was measured. Results: Except for PCWP (P < 0.001) and mean pulmonary artery pressure (P < 0.001) no differences in age, baseline characteristics, and ejection fraction were observed between both groups, and volume load significantly increased PCWP in both groups (group A: P < 0.001 and group B: P < 0.001) without any change in heart rate. Interestingly, volume load significantly increased CI in group A (P < 0.001) but not in group B (P = 0.654), and the Starling curves revealed a higher CI at any given PCWP in group A together with significantly higher iNOS gene expression (P = 0.009). Conclusions: In HTx, volume load increases FP and unmasks the presence of left ventricular diastolic dysfunction. Interestingly, following saline load group B shows a blunted Starling response, with higher PCWP and lack of CI increase at any given PCWP. The higher iNOS gene expression level in group A suggests a potential role of NO as mediator of diastolic function.

A Steep Increase in the HeartLogic Index Predicts COVID-19 Disease in an Advanced Heart Failure Patient.

We present a patient with severe nonischemic cardiomyopathy in whom the HeartLogic algorithm was activated on her Boston Scientific cardioverter defibrillator. She had an out-of-alert state for several months and had clinically "stable" heart failure with no hospitalizations in the last 6 months. A sudden and fast increase of the HeartLogic index preceded her presentation in the emergency ward by several days. The detailed readout of HeartLogic however had some atypical features for heart failure decompensation. The patient presented at the emergency department with an increased dyspnea and a dry cough. Clinical exam showed desaturation and was suggestive for an acute respiratory infection. Subsequent imaging with CT thorax and nasopharyngeal real-time polymerase chain reaction (RT-PCR) confirmed SARS-CoV-2 viral pneumonia (COVID-19). This case illustrates that a timely and detailed analysis of HeartLogic alerts could help in the early differentiation of disease in patients with severe heart failure.

Impact of sacubitril/valsartan on heart failure admissions: insights from real-world patient prescriptions.

BACKGROUND: Sacubitril/valsartan reduced heart failure (HF)-admissions and cardiovascular mortality in the PARADIGM-HF-trial. However, real-world patients are often frailer and less able to tolerate high doses of sacubitril/valsartan. METHODS: We performed a retrospective analysis of consecutive patients prescribed sacubitril/valsartan in a single tertiary HF-clinic between December 2016 and January 2018. HF-admissions were assessed in a paired fashion, comparing the amount of antecedent HF-episodes with incident HF-episodes after the initiation. Baseline risk for adverse events was assessed by the EMPHASIS-HF-risk-score. RESULTS: A total of 201-HF-patients were retrospectively identified (age = 68 ± 11 years, ejection fraction = 29 ± 8%). Real world patients were older, had higher serum creatinine and a higher New-York Heart-Association (NYHA)-class (p < .05 for all) than in the PARADIGM-HF trial. Over a mean duration of 221 ± 114 days after initiation of sacubitril/valsartan a total of 23-individual patients experienced at least one HF-episodes. Over the same time period preceding initiation of sacubitril/valsartan, 51 individual patients experienced a HF-episodes (p < .001). Sacubitril/valsartan significantly reduced the rate of incident vs. antecedent HF-admissions, in patients with low or high baseline NYHA-class (II vs. III and IV; p value = 0.019 respectively p = .004) or patients with an EMPHASIS-HF risk score below or above the mean (p = .002 respectively p = .016). Patients older than 75-years exhibited a trend towards HF-reduction. Higher doses of sacubitril/valsartan were associated with more reduction in incident versus antecedent HF-episodes. CONCLUSION: Despite being frailer and older, real-world patients exhibit a significant and early reduction in incident HF-hospitalisations following initiation of sacubitril/valsartan. Higher doses might be associated with more reduction in HF-admissions, underscoring the importance of dose uptitration.

Effects of sacubitril/valsartan on functional status and exercise capacity in real-world patients.

Background: Sacubitril/valsartan significantly reduced heart failure(HF) hospitalisations and mortality in the PARADIGM-HF-trial. However real-world data on symptomatic and functional improvement are lacking. Methods: Between December 2016 and January 2018, we retrospectively collected baseline and follow-up data including New York Heart Association (NYHA)-functional class and Cardio-pulmonary exercise data(CPET) in all HF-patients receiving sacubitril/valsartan. Additionally, in patients with an implantable electric cardiovascular device (IECD) enrolled in remote telemonitoring, we quantified patient level activity before and after initiation. Results: A total of 201 patients (82% males) were identified. NYHA-functional class was reassessed after an average of 221 ± 114 days. Overall, 3.3% of patients improved 2 NYHA classes, 28.7% improved 1 NYHA class, 64% remained stable and 4% deteriorated 1 NYHA class. Patients with symptomatic improvement exhibited a larger reduction in Left Ventricular End Systolic Volume(LVESV) and a larger increase in Left Ventricular Ejection Fraction(LVEF[p-value both <.05]). In total, 110 patients (55%) were equipped with an IECD capable of quantifying outpatient activity-level. On an average of 364 days before sacubitril/valsartan, an activity expressed as %-of-the-day was 13 ± 2%, vs. 18 ± 3% the 364 days following sacubitril/valsartan initiation. Signifying a 38% improvement in the out-patient activity level. CPET-data was obtained in paired-fashion in 45 patients (22%). VO2max at baseline (14.7 ± 3.8 mL/kg/min) did not significantly change at follow-up (14.1 ± 4.7 mL/min/kg; p = .237). Conclusion: Real-world patients exhibit significant symptomatic and functional improvement following the initiation of sacubitril/valsartan. However, larger prospective studies are necessary to assess the impact of sacubitril/valsartan on indices of maximal exercise performance measured during CPET.