Assessment and Therapeutic Modulation of Heart Rate Variability: Potential Implications in Patients with COVID-19.

Cardiac damage has been attributed to SARS-CoV-2-related pathology contributing to increased risk of vascular events. Heart rate variability (HRV) is a parameter of functional neurocardiac integrity with low HRV constituting an independent predictor of cardiovascular mortality. Whether structural cardiac damage translates into neurocardiac dysfunction in patients infected with SARS-CoV-2 remains poorly understood. Hypothesized mechanisms of possible neurocardiac dysfunction in COVID-19 comprise direct systemic neuroinvasion of autonomic control centers, ascending virus propagation along cranial nerves and cardiac autonomic neuropathy. While the relationship between the autonomic nervous system and the cytokine cascade in general has been studied extensively, the interplay between the inflammatory response caused by SARS-CoV-2 and autonomic cardiovascular regulation remains largely unclear. We reviewed the current literature on the potential diagnostic and prognostic value of autonomic neurocardiac function assessment via analysis of HRV including time domain and spectral analysis techniques in patients with COVID-19. Furthermore, we discuss potential therapeutic targets of modulating neurocardiac function in this high-risk population including HRV biofeedback and the impact of long COVID on HRV as well as the approaches of clinical management. These topics might be of particular interest with respect to multimodal pandemic preparedness concepts.

Telemedical cardiac risk assessment by implantable cardiac monitors in patients after myocardial infarction with autonomic dysfunction (SMART-MI-DZHK9): a prospective investigator-initiated, randomised, multicentre, open-label, diagnostic trial.

BACKGROUND: Cardiac autonomic dysfunction after myocardial infarction identifies patients at high risk despite only moderately reduced left ventricular ejection fraction. We aimed to show that telemedical monitoring with implantable cardiac monitors in these patients can improve early detection of subclinical but prognostically relevant arrhythmic events. METHODS: We did a prospective investigator-initiated, randomised, multicentre, open-label, diagnostic trial at 33 centres in Germany and Austria. Survivors of acute myocardial infarction with left ventricular ejection fraction of 36-50% had biosignal analysis for assessment of cardiac autonomic function. Patients with abnormal periodic repolarisation dynamics (≥5·75 deg2) or abnormal deceleration capacity (≤2·5 ms) were randomly assigned (1:1) to telemedical monitoring with implantable cardiac monitors or conventional follow-up. Primary endpoint was time to detection of serious arrhythmic events defined by atrial fibrillation 6 min or longer, atrioventricular block class IIb or higher and fast non-sustained (>187 beats per min; ≥40 beats) or sustained ventricular tachycardia or fibrillation. This study is registered with ClinicalTrials.gov, NCT02594488. FINDINGS: Between May 12, 2016, and July 20, 2020, 1305 individuals were screened and 400 patients at high risk were randomly assigned (median age 64 years [IQR 57-73]); left ventricular ejection fraction 45% [40-48]) to telemedical monitoring with implantable cardiac monitors (implantable cardiac monitor group; n=201) or conventional follow-up (control group; n=199). During median follow-up of 21 months, serious arrhythmic events were detected in 60 (30%) patients of the implantable cardiac monitor group and 12 (6%) patients of the control group (hazard ratio 6·33 [IQR 3·40-11·78]; p<0·001). An improved detection rate by implantable cardiac monitors was observed for all types of serious arrhythmic events: atrial fibrillation 6 min or longer (47 [23%] patients vs 11 [6%] patients; p<0·001), atrioventricular block class IIb or higher (14 [7%] vs 0; p<0·001) and ventricular tachycardia or ventricular fibrillation (nine [4%] patients vs two [1%] patients; p=0·054). INTERPRETATION: In patients at high risk after myocardial infarction and cardiac autonomic dysfunction but only moderately reduced left ventricular ejection fraction, telemedical monitoring with implantable cardiac monitors was highly effective in early detection of subclinical, prognostically relevant serious arrhythmic events. FUNDING: German Centre for Cardiovascular Research (DZHK) and Medtronic Bakken Research Center.

Vessel fractional flow reserve (vFFR) for the assessment of stenosis severity: the FAST II study.

BACKGROUND: Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) is superior to angiography-guided PCI. The clinical uptake of FFR has been limited, however, by the need to advance a wire in the coronary artery, the additional time required and the need for hyperaemic agents which can cause patient discomfort. FFR derived from routine coronary angiography eliminates these issues. AIMS: The aim of this study was to assess the diagnostic performance and accuracy of three-dimensional quantitative coronary angiography (3D-QCA)-based vessel FFR (vFFR) compared to pressure wire-based FFR (≤0.80). METHODS: The FAST II (Fast Assessment of STenosis severity) study was a prospective observational multicentre study designed to evaluate the diagnostic accuracy of vFFR compared to the reference standard (pressure wire-based FFR ≤0.80). A total of 334 patients from six centres were enrolled. Both site-determined and blinded independent core lab vFFR measurements were compared to FFR. RESULTS: The core lab vFFR was 0.83±0.09 and pressure wire-based FFR 0.83±0.08. A good correlation was found between core lab vFFR and pressure wire-based FFR (R=0.74; p<0.001; mean bias 0.0029±0.0642). vFFR had an excellent diagnostic accuracy in identifying lesions with an invasive wire-based FFR ≤0.80 (area under the curve [AUC] 0.93; 95% confidence interval [CI]: 0.90-0.96; p<0.001). Positive predictive value, negative predictive value, diagnostic accuracy, sensitivity and specificity of vFFR were 90%, 90%, 90%, 81% and 95%, respectively. CONCLUSIONS: 3D-QCA-based vFFR has excellent diagnostic performance to detect FFR ≤0.80. The study was registered on clinicaltrials.gov under identifier NCT03791320.

Left-Atrial Appendage Thrombosis in Patients With Severe Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation.

BACKGROUND: Data about the impact of left-atrial appendage thrombosis (LAAT) on early safety and mortality in patients undergoing transfemoral transcatheter aortic valve implantation (TF-TAVI) are scarce. We aimed to investigate the prevalence and predictors of LAAT and the outcome associated with this condition in patients treated by TF-TAVI. METHODS: Retrospective data analysis was derived from a prospective single-centre registry comparing patients with and without LAAT regarding early safety at 30 days, according to Valve Academic Research Consortium-2 (VARC-2) and 2-year mortality. RESULTS: LAAT was found in 7.6% of the whole cohort (n = 2527) and in 16.6% in those patients with known pre-existing atrial fibrillation (AF cohort, n = 1099). Compared with controls, patients with LAAT were sicker, indicated by a higher Society of Thoracic Surgeons (STS) score and burden of comorbidities. Neither VARC-2-defined early safety at 30 days nor the rate of stroke was different between LAAT and controls in both the whole (early safety: 29.2% vs 24.2%, P = 0.123; stroke: 5.9% vs 4.7%, P = 0.495) and AF cohort (early safety: 29.1% vs 22.9%, P = 0.072; stroke: 5.6% vs 3.3%, P = 0.142). Evaluating the whole cohort in a univariate analysis, the 2-year mortality was significantly higher in LAAT compared with controls (hazard ratio, 1.41; 95% confidence interval, 1.07-1.86; P = 0.014). However, multivariate analysis of the whole cohort and the AF cohort revealed no association between LAAT and 2-year mortality. CONCLUSIONS: LAAT was frequent in patients undergoing TF-TAVI- in particular, in patients with histories of AF-but it was not associated with an increase in periprocedural complications and did not predict 2-year mortality.

Hemodynamic Assessment of Aortic Regurgitation After Transcatheter Aortic Valve Replacement: The Diastolic Pressure-Time Index.

OBJECTIVES: Assessment of aortic regurgitation (AR) immediately after transcatheter aortic valve replacement (TAVR) is essential to guide further intervention in cases of relevant AR. It was the aim of this study to identify a simple and reproducible hemodynamic parameter for the assessment of AR. BACKGROUND: Relevant AR after TAVR is present in up to 21% of cases and might be associated with adverse long-term outcomes. METHODS: Three hundred sixty-two consecutive patients who were treated with TAVR for symptomatic aortic valve stenosis were analyzed. AR was assessed by aortic root angiography according to the Sellers classification. For hemodynamic evaluation, the diastolic pressure-time (DPT) index was calculated after TAVR: the area between the aortic and left ventricular pressure-time curves was measured during diastole and divided by the duration of diastole to calculate the DPT index. The DPT index was finally adjusted for the respective systolic blood pressure: DPT indexadj = (DPT index/systolic blood pressure) × 100. RESULTS: Patients with angiographically nonrelevant AR (grade <2) had higher DPT indexadj (30.7 ± 6.8) compared with those with relevant AR (grade ≥2) (26.2 ± 5.8) (p < 0.05). Patients with DPT indexadj ≤27.9 had significantly higher 1-year mortality risk in comparison with those with DPT indexadj >27.9: 41.4% versus 13.5% (hazard ratio: 3.8; 95% confidence interval: 2.4 to 5.9; p [log rank-test] < 0.001). In multivariate regression analysis, DPT indexadj ≤27.9 was the strongest independent predictor of 1-year mortality (hazard ratio: 2.5; 95% confidence interval: 1.8 to 3.7; p < 0.001). CONCLUSIONS: DPT indexadj is a simple, investigator-independent parameter that should be considered to differentiate between relevant and nonrelevant AR after TAVR.

Assessment of acute changes in ventricular volumes, function, and strain after interventional edge-to-edge repair of mitral regurgitation using cardiac magnetic resonance imaging.

AIMS: Whereas haemodynamic and echocardiographic studies suggest benefits for left ventricular (LV) function and cardiac output following reduction in LV preload by interventional edge-to-edge repair for mitral regurgitation (MR), there is limited data on volumetric and functional LV and right ventricular (RV) changes using cardiac magnetic resonance (CMR) imaging. METHODS AND RESULTS: Patients with moderate to severe MR and high surgical risk underwent MitraClip-implantation and CMR imaging before and within 7 days after the procedure. In addition to volumetric and flow studies, myocardial feature tracking (FT) technology for quantification of myocardial strain was applied. Twenty patients (age: 76 ± 8 years) with functional (n = 15) or degenerative MR (n = 5) with a mean logistic Euroscore I of 33 ± 16 underwent both successful MitraClip implantation and CMR imaging. MR fraction (36 ± 10 vs. 19 ± 12%; P < 0.001) and LV end-diastolic volume (115 ± 36 vs. 105 ± 41 mL/m2; P = 0.002) decreased significantly, whereas LV ejection fraction (42 ± 15 vs. 41 ± 16%, P = 0.8) and cardiac index (1.7 ± 0.5 vs. 1.8 ± 0.4 L/min/m2, P = 0.4) remained unchanged. MitraClip implantation resulted in a significant impairment of circumferential (-12.8 ± 4.8 vs. -8.2 ± 3.3; P = 0.002) and radial strain (15.4 ± 7.7 vs. 9.6 ± 5.3; P = 0.02) on basal short-axis view. On RV level, there were no significant changes in end-diastolic volume (83 ± 19 vs. 84 ± 18 mL/m2, P = 0.8), ejection fraction (42 ± 9 vs. 43 ± 11%, P = 0.8), or tricuspid regurgitation fraction (24 ± 17 vs. 25 ± 19%, P = 0.7). MitraClip implantation led to a significant improvement in New York Heart Association functional class (patients in functional class III-IV pre 100% vs. post 45%; P < 0.001). CONCLUSION: In severely compromised patients, marked reduction in MR by MitraClip implantation might not result in immediate improved cardiac output and effective biventricular forward flow.

Cost-utility of transcatheter aortic valve implantation for inoperable patients with severe aortic stenosis treated by medical management: a UK cost-utility analysis based on patient-level data from the ADVANCE study.

OBJECTIVE: To use patient-level data from the ADVANCE study to evaluate the cost-effectiveness of transcatheter aortic valve implantation (TAVI) compared to medical management (MM) in patients with severe aortic stenosis from the perspective of the UK NHS. METHODS: A published decision-analytic model was adapted to include information on TAVI from the ADVANCE study. Patient-level data informed the choice as well as the form of mathematical functions that were used to model all-cause mortality, health-related quality of life and hospitalisations. TAVI-related resource use protocols were based on the ADVANCE study. MM was modelled on publicly available information from the PARTNER-B study. The outcome measures were incremental cost-effectiveness ratios (ICERs) estimated at a range of time horizons with benefits expressed as quality-adjusted life-years (QALY). Extensive sensitivity/subgroup analyses were undertaken to explore the impact of uncertainty in key clinical areas. RESULTS: Using a 5-year time horizon, the ICER for the comparison of all ADVANCE to all PARTNER-B patients was £13 943 per QALY gained. For the subset of ADVANCE patients classified as high risk (Logistic EuroSCORE >20%) the ICER was £17 718 per QALY gained). The ICER was below £30 000 per QALY gained in all sensitivity analyses relating to choice of MM data source and alternative modelling approaches for key parameters. When the time horizon was extended to 10 years, all ICERs generated in all analyses were below £20 000 per QALY gained. CONCLUSION: TAVI is highly likely to be a cost-effective treatment for patients with severe aortic stenosis.

The prognostic utility of the SYNTAX score on 1-year outcomes after revascularization with zotarolimus- and everolimus-eluting stents: a substudy of the RESOLUTE All Comers Trial.

OBJECTIVES: This study assessed the ability of the SYNTAX score (SXscore) to stratify risk in patients treated with percutaneous coronary intervention (PCI) using zotarolimus-eluting or everolimus-eluting stents. BACKGROUND: The SXscore can identify patients treated with PCI who are at highest risk of adverse events. METHODS: The SXscore was calculated prospectively in 2,033 of the 2,292 patients enrolled in the RESOLUTE All Comers study (RESOLUTE III All Comers Trial: A Randomized Comparison of a Zotarolimus-Eluting Stent With an Everolimus-Eluting Stent for Percutaneous Coronary Intervention). Clinical outcomes in terms of a patient-oriented composite endpoint (POCE) of all-cause death, myocardial infarction (MI), and repeat revascularization; the individual components of POCE; target lesion failure (TLF) (a composite of cardiac death, target-vessel MI, and clinically driven target lesion revascularization); and stent thrombosis were subsequently stratified according to SXscore tertiles: SXscore(LOW) ≤ 9 (n = 698), 9 17 (n = 659). RESULTS: At 12-month follow-up, rates of POCE, MI, repeat revascularization, TLF, and the composite of death/MI were all significantly higher in patients in the highest SXscore tercile. Rates of stent thrombosis were all highest in the SXscore(HIGH) tertile (p > 0.05). After multivariate adjustment, the SXscore was identified as an independent predictor of POCE, MI, repeat revascularization, and TLF (p < 0.05 for all). At 12-month follow-up, the SXscore, ACEF score, and Clinical SXscore had C-statistics of 0.57, 0.78, and 0.67, respectively, for mortality and of 0.62, 0.56, 0.63, respectively, for POCE. No significant between-stent differences were observed for TLF or POCE in any of the SXscore tertiles. CONCLUSIONS: The SYNTAX score is able to stratify risk amongst an all-comers population treated with PCI with second-generation drug-eluting stents (DES); however, improvements can be made with the inclusion of clinical variables. (RESOLUTE III All Comers Trial: A Randomized Comparison of a Zotarolimus-Eluting Stent With an Everolimus-Eluting Stent for Percutaneous Coronary Intervention; NCT00617084).

Value of the SYNTAX score for risk assessment in the all-comers population of the randomized multicenter LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial.

OBJECTIVES: We aimed to assess the predictive value of the SYNTAX score (SXscore) for major adverse cardiac events in the all-comers population of the LEADERS (Limus Eluted from A Durable versus ERodable Stent coating) trial. BACKGROUND: The SXscore has been shown to be an effective predictor of clinical outcomes in patients with multivessel disease undergoing percutaneous coronary intervention. METHODS: The SXscore was prospectively collected in 1,397 of the 1,707 patients enrolled in the LEADERS trial (patients after surgical revascularization were excluded). Post hoc analysis was performed by stratifying clinical outcomes at 1-year follow-up, according to 1 of 3 SXscore tertiles. RESULTS: The 1,397 patients were divided into tertiles based on the SXscore in the following fashion: SXscore8 and 16 (SXhigh) (n=461). At 1-year follow-up, there was a significantly lower number of patients with major cardiac event-free survival in the highest tertile of SXscore (SXlow=92.2%, SXmid=91.1%, and SXhigh=84.6%; p<0.001). Death occurred in 1.5% of SXlow patients, 2.1% of SXmid patients, and 5.6% of SXhigh patients (hazard ratio [HR]: 1.97, 95% confidence interval [CI]: 1.29 to 3.01; p=0.002). The myocardial infarction rate tended to be higher in the SXhigh group. Target vessel revascularization was 11.3% in the SXhigh group compared with 6.3% and 7.8% in the SXlow and SXmid groups, respectively (HR: 1.38, 95% CI: 1.1 to 1.75; p=0.006). Composite of cardiac death, myocardial infarction, and clinically indicated target vessel revascularization was 7.8%, 8.9%, and 15.4% in the SXlow, SXmid, and SXhigh groups, respectively (HR: 1.47, 95% CI: 1.19 to 1.81; p<0.001). CONCLUSIONS: The SXscore, when applied to an all-comers patient population treated with drug-eluting stents, may allow prospective risk stratification of patients undergoing percutaneous coronary intervention. (LEADERS Trial Limus Eluted From A Durable Versus ERodable Stent Coating; NCT00389220).

The utility of trans-catheter aortic valve replacement after commercialization: does the European experience provide a glimpse into the future use of this technology in the United States?

Treatment of aortic stenosis remains challenging in older individuals, as their perioperative mortality for open heart surgery is increased due to comorbidities. Transcatheter aortic valve implantation using the CoreValve ReValving System (Medtronic, Minneapolis, USA) and the Edwards SAPIEN transcatheter heart valve (THV; Edwards Lifescience, Irvine, California, USA) represents an alternative to conventional valve replacement in elderly patients that have a high risk for conventional surgery. This article summarizes the evidence-base from recent clinical trials. The early results of these landmark studies suggest that transcatheter aortic valve implantation with either one of the prosthesis is feasible, safe, improves hemodynamics and, therefore, might be an alternative to conventional aortic valve replacement in very high-risk patients. However, all of the available transcatheter heart valves have certain disadvantages, limiting their use in daily clinical practice. The process of decision making, which valve to use and which access route to choose is illustrated in this article through clinical case scenarios. Additionally, the lessons learned thus far from the European perspective and the potential impact on the future use in the US are discussed. Despite of the progress in this field, we are still lacking an optimal transcatheter heart valve. Once it is available, we can take the plunge to compare transcatheter valve implantation with convention surgery in severe aortic stenosis!

Procedural and 30-day outcomes following transcatheter aortic valve implantation using the third generation (18 Fr) corevalve revalving system: results from the multicentre, expanded evaluation registry 1-year following CE mark approval.

AIMS: To describe the procedural performance and 30-day outcomes following implantation using the 18 Fr CoreValve Revalving System (CRS) as part of the multicentre, expanded evaluation registry, 1-year after obtaining CE mark approval. METHODS AND RESULTS: Patients with symptomatic severe aortic stenosis and logistic Euroscore > or =15%, or age > or =75 years, or age > or =65 years associated with pre-defined risk factors, and for whom a physician proctor and a clinical specialist were in attendance during the implantation and who collected the clinical data, were included. From April 2007, to April 2008, 646 patients with a mean age of 81 +/- 6.6 years, mean aortic valve area 0.6 +/- 0.2 cm2, and logistic EuroSCORE of 23.1 +/- 13.8% were recruited. After valve implantation, the mean transaortic valve gradient decreased from 49.4 +/- 13.9 to 3 +/- 2 mmHg. All patients had paravalvular aortic regurgitation < or = grade 2. The rate of procedural success was 97%. The procedural mortality rate was 1.5%. At 30 days, the all-cause mortality rate (i.e, including procedural) was 8% and the combined rate of death, stroke and myocardial infarction was 9.3%. CONCLUSIONS: The results of this study demonstrate the high rate of procedural success and a low 30-day mortality in a large cohort of high-risk patients undergoing transcatheter aortic valve implantation (TAVI) with the CRS.

Percutaneous coronary angioplasty compared with exercise training in patients with stable coronary artery disease: a randomized trial.

BACKGROUND: Regular exercise in patients with stable coronary artery disease has been shown to improve myocardial perfusion and to retard disease progression. We therefore conducted a randomized study to compare the effects of exercise training versus standard percutaneous coronary intervention (PCI) with stenting on clinical symptoms, angina-free exercise capacity, myocardial perfusion, cost-effectiveness, and frequency of a combined clinical end point (death of cardiac cause, stroke, CABG, angioplasty, acute myocardial infarction, and worsening angina with objective evidence resulting in hospitalization). METHODS AND RESULTS: A total of 101 male patients aged < or =70 years were recruited after routine coronary angiography and randomized to 12 months of exercise training (20 minutes of bicycle ergometry per day) or to PCI. Cost efficiency was calculated as the average expense (in US dollars) needed to improve the Canadian Cardiovascular Society class by 1 class. Exercise training was associated with a higher event-free survival (88% versus 70% in the PCI group, P=0.023) and increased maximal oxygen uptake (+16%, from 22.7+/-0.7 to 26.2+/-0.8 mL O2/kg, P<0.001 versus baseline, P<0.001 versus PCI group after 12 months). To gain 1 Canadian Cardiovascular Society class, 6956 dollars was spent in the PCI group versus 3429 dollars in the training group (P<0.001). CONCLUSIONS: Compared with PCI, a 12-month program of regular physical exercise in selected patients with stable coronary artery disease resulted in superior event-free survival and exercise capacity at lower costs, notably owing to reduced rehospitalizations and repeat revascularizations.