Jonas Lanz

Development of a bead-based multiplex assay for the simultaneous detection of porcine inflammation markers using xMAP technology.

Commercially available assays for the simultaneous detection of multiple inflammatory and cardiac markers in porcine blood samples are currently lacking. Therefore, this study was aimed at developing a bead‐based, multiplexed flow cytometric assay to simultaneously detect porcine cytokines [interleukin (IL)‐1β, IL‐6, IL‐10, and tumor necrosis factor alpha], chemokines (IL‐8 and monocyte chemotactic protein 1), growth factors [basic fibroblast growth factor (bFGF), vascular endothelial growth factor, and platelet‐derived growth factor‐bb], and injury markers (cardiac troponin‐I) as well as complement activation markers (C5a and sC5b‐9). The method was based on the Luminex xMAP technology, resulting in the assembly of a 6‐ and 11‐plex from the respective individual singleplex situation. The assay was evaluated for dynamic range, sensitivity, cross‐reactivity, intra‐assay and interassay variance, spike recovery, and correlation between multiplex and commercially available enzyme‐linked immunosorbent assay as well as the respective singleplex. The limit of detection ranged from 2.5 to 30,000 pg/ml for all analytes (6‐ and 11‐plex assays), except for soluble C5b‐9 with a detection range of 2–10,000 ng/ml (11‐plex). Typically, very low cross‐reactivity (<3% and <1.4% by 11‐ and 6‐plex, respectively) between analytes was found. Intra‐assay variances ranged from 4.9 to 7.4% (6‐plex) and 5.3 to 12.9% (11‐plex). Interassay variances for cytokines were between 8.1 and 28.8% (6‐plex) and 10.1 and 26.4% (11‐plex). Correlation coefficients with singleplex assays for 6‐plex as well as for 11‐plex were high, ranging from 0.988 to 0.997 and 0.913 to 0.999, respectively. In this study, a bead‐based porcine 11‐plex and 6‐plex assay with a good assay sensitivity, broad dynamic range, and low intra‐assay variance and cross‐reactivity was established. These assays therefore represent a new, useful tool for the analysis of samples generated from experiments with pigs.

Addition of dextran sulfate to blood cardioplegia attenuates reperfusion injury in a porcine model of cardiopulmonary bypass

OBJECTIVE Contact of blood with artificial surfaces and air as well as ischemia/reperfusion injury to the heart and lungs mediate systemic and local inflammation during cardiopulmonary bypass (CPB). Activation of complement and coagulation cascades leads to and accompanies endothelial cell damage. Therefore, endothelial-targeted cytoprotection with the complement inhibitor and endothelial protectant dextran sulfate (DXS, MW 5000) may attenuate CBP-associated myocardial and pulmonary injury. METHODS Eighteen pigs (DXS, n=10; phosphate buffered saline [PBS], n=8) underwent standard cardiopulmonary bypass. After aortic cross-clamping, cardiac arrest was initiated with modified Buckberg blood cardioplegia (BCP), repeated after 30 and 60 min with BCP containing either DXS (300 mg/10 ml, equivalent to 5mg/kg) or 10 ml of PBS. Following 30 min reperfusion, pigs were weaned from CPB. During 2h of observation, cardiac function was monitored by echocardiography and invasive pressure measurements. Inflammatory and coagulation markers were assessed regularly. Animals were then sacrificed and heart and lungs analyzed. RESULTS DXS significantly reduced CK-MB levels (43.4+/-14.8 ng/ml PBS, 35.9+/-11.1 ng/ml DXS, p=0.042) and significantly diminished cytokine release: TNFalpha (1507.6+/-269.2 pg/ml PBS, 222.1+/-125.6 pg/ml DXS, p=0.0071), IL1beta (1081.8+/-203.0 pg/ml PBS, 110.7+/-79.4 pg/ml DXS, p=0.0071), IL-6 (173.0+/-91.5 pg/ml PBS, 40.8+/-19.4 pg/ml DXS, p=0.002) and IL-8 (304.6+/-81.3 pg/ml PBS, 25.4+/-14.2 pg/ml DXS, p=0.0071). Tissue endothelin-1 levels were significantly reduced (6.29+/-1.90 pg/100mg PBS, 3.55+/-1.15 pg/100mg DXS p=0.030) as well as thrombin-anti-thrombin formation (20.7+/-1.0 microg/ml PBS, 12.8+/-4.1 microg/ml DXS, p=0.043). Also DXS reduced cardiac and pulmonary complement deposition, neutrophil infiltration, hemorrhage and pulmonary edema (measured as lung water content, 81+/-3% vs 78+/-3%, p=0.047), indicative of attenuated myocardial and pulmonary CPB-injury. Diastolic left ventricular function (measured as dp/dt(min)), pulmonary artery pressure (21+/-3 mmHg PBS, 19+/-3 mmHg DXS, p=0.002) and right ventricular pressure (21+/-1 mmHg PBS, 19+/-3 mmHg DXS p=0.021) were significantly improved with the use of DXS. CONCLUSIONS Addition of DXS to the BCP solution ameliorates post-CPB injury and to a certain extent improves cardiopulmonary function. Endothelial protection in addition to myocyte protection may improve post-CPB outcome and recovery.

The impact of functional vs degenerative mitral regurgitation on clinical outcomes among patients undergoing transcatheter aortic valve implantation.

Background Among patients undergoing transcatheter aortic valve implantation (TAVI), concomitant mitral regurgitation (MR) has been associated with adverse prognosis. We aimed to assess long‐term clinical outcomes according to MR etiology. Methods In a single‐center registry of consecutive patients undergoing TAVI, we investigated the impact of functional (FMR) vs degenerative (DMR) MR on cardiovascular (CV) mortality throughout 2 years of follow‐up. Results Among 603 patients (mean age 82.4 ± 5.7 years, 55% female) undergoing TAVI, 149 patients had moderate or severe MR (24.7%). Functional MR and DMR were documented in 53 (36%) and 96 (64%) patients, respectively. At 2 years, patients with FMR and DMR had higher rates of CV mortality (30.2% vs 32.4%) as compared with patients with no MR (14.6%; FMR vs no MR: hazard ratio [HR] 2.32, 95% CI 1.34‐4.02, P = .003; DMR vs no MR: HR 2.56, 95% CI 1.66‐3.96, P < .001). In adjusted analyses, DMR was associated with an increased risk of CV mortality throughout the 2‐year follow‐up (adjusted HR 2.21, 95% CI 1.4‐3.49, P = .001) as compared with FMR (adjusted HR 1.13, 95% CI 0.59‐2.18, P = .707). Relevant MR was postprocedurally significantly reduced in both the DMR and FMR groups, whereas improvement of a decreased left ventricular ejection fraction was predominantly seen in the FMR group as compared with baseline. Conclusion Patients with severe, symptomatic aortic stenosis undergoing TAVI complicated by moderate or severe MR portend impaired prognosis. Particularly, patients with DMR are at increased risk for CV mortality during long‐term follow‐up.

Early versus newer generation devices for transcatheter aortic valve implantation in routine clinical practice: a propensity score matched analysis

Aim Contemporary data comparing early versus newer generation transcatheter heart valve (THV) devices in routine clinical practice are lacking. We sought to compare the safety and efficacy of early versus newer generation THVs in unselected patients undergoing transcatheter aortic valve implantation (TAVI). Methods and results We performed a propensity score matched analysis of patients undergoing transfemoral TAVI at a single centre with early versus newer generation devices between 2007 and 2016. Patients were matched for balloon-expandable versus self-expandable valves and Society of Thoracic Surgeons score. The primary end point was the Valve Academic Research Consortium (VARC)-2 early safety composite end point at 30 days. Among the 391 matched pairs, no differences between early (21.2%) and newer generation (20.8%) THVs regarding the early safety composite end point (HR 0.98, 95% CI 0.72 to 1.33, P=0.88) were observed. The rates of valve embolisation (0.8% vs 4.2%, P=0.005), bleeding events (24.8% vs 32.0%, P=0.028) and moderate-to-severe paravalvular regurgitation (PVR) (3.1% vs 12.1%, P<0.001) were lower among patients receiving newer generation devices. Conversely, patients treated with early generation THVs less frequently experienced annulus rupture (0% vs 2.0%, P=0.008). Conclusion Newer compared with early generation THV devices were associated with a lower rate of valve embolisation, PVR and bleeding events.

Transcatheter aortic valve thrombosis: incidence, clinical presentation and long-term outcomes

Aims To assess the incidence, management and long-term outcomes of transcatheter heart valve thrombosis (THVT). Methods and results Between August 2007 and February 2016, 1396 patients were included in the Bern TAVI Registry and prospectively followed-up through echocardiographic and clinical evaluation. THVT was suspected in case of: (i) a mean transvalvular pressure gradient greater than 20 mmHg at transthoracic echocardiography, or (ii) an increase of more than 50% of the mean transvalvular pressure gradient compared with previous measurements or (iii) new symptoms or signs of heart failure with the presence of thrombus documented by transoesophageal echocardiography or multi-slice computed tomography. THVT occurred in 10 patients (0.71%) at variable time points after TAVI. Increased transvalvular pressure gradients were recorded in all patients and 7 out of 10 patients were symptomatic. Oral anticoagulant therapy (with vitamin K antagonists or non-Vitamin K antagonists) was initiated in all but two patients and resulted in normalization of transvalvular pressure gradients and amelioration of clinical status within 1 month. At long-term follow-up (between 10 and 25 months after valve thrombosis), echocardiographic findings were stable and no adverse events were reported. Conclusion THVT is rarely detected at routine clinical and echocardiographic evaluation after TAVI. Oral anticoagulation appears effective to normalize transvalvular gradients in the majority of cases with stable clinical and haemodynamic evolution during long-term follow-up.

Prognostic impact of invasive haemodynamic measurements in combination with clinical and echocardiographic characteristics on two-year clinical outcomes of patients undergoing transcatheter aortic valve implantation

AIMS The aim of the study was to evaluate the prognostic utility of right heart catheterisation (RHC)-derived measures among patients undergoing transcatheter aortic valve implantation (TAVI). METHODS AND RESULTS Data of 469 patients included in the Bern TAVI Registry between August 2007 and December 2012 and undergoing preoperative RHC were analysed. The relationship between haemodynamic parameters and survival was evaluated with Cox proportional hazards models. At two-year follow-up, 118 patients had died (25.1%). At multivariable analysis, diabetes (hazard ratio [HR] 1.95, 95% confidence interval [CI]: 1.28-2.96, p=0.001), transapical access (HR 1.66, 95% CI: 1.07-2.56, p=0.02), and moderate or severe mitral regurgitation (HR 1.55, 95% CI: 1.00-2.39, p=0.04) were independent predictors of two-year mortality, whereas no correlation between RHC-derived measures and mortality was found. Furthermore, the addition of haemodynamic variables did not significantly improve the prognostic power of a model incorporating clinical and echocardiographic data (Harrells C-index: 0.667, 95% CI: 0.615-0.719 vs. 0.662, 95% CI: 0.612-0.713, p=0.47). CONCLUSIONS On the basis of a comprehensive clinical and echocardiographic evaluation, RHC performed prior to TAVI does not add incremental prognostic value.

Effects of coronary artery disease in patients undergoing transcatheter aortic valve implantation: A study of age- and gender-matched cohorts

BACKGROUND The prognostic role of concomitant coronary artery disease (CAD) among patients undergoing transcatheter aortic valve implantation (TAVI) is still uncertain. METHODS Data from the Bern TAVI Registry and the Bern PCI Registry were analyzed. Patients with concomitant CAD undergoing TAVI (TAVI+CAD) were age- and gender-matched to the following two cohorts: patients without CAD undergoing TAVI (TAVI-noCAD) and patients with stable CAD undergoing percutaneous coronary intervention (CAD-noAS). Major adverse cardiovascular and cerebrovascular events (MACCE), defined as the composite of cardiovascular death, myocardial infarction, or cerebrovascular events, represented the primary endpoint at 1-year. RESULTS Out of 9478 procedures performed between 2007 and 2013 (807 TAVI; 8671 PCI), three cohorts, each including 248 subjects, were derived. At 1-year, MACCE were significantly increased among TAVI+CAD compared with TAVI-noCAD (16.8% vs. 9.8%, hazard ratio, HR, 1.75, 95% confidence intervals, CI, 1.06-2.89, p=0.030) and CAD-noAS patients (16.8% vs. 9.5%, HR 1.85, 95%CI 1.11-3.09, p=0.018) whereas no difference was found between TAVI-noCAD and CAD-noAS patients. The higher rate of MACCE among TAVI+CAD patients was mainly driven by an increased risk of cardiovascular mortality compared with the TAVI-noCAD (HR 1.86, 95%CI 1.03-3.36, p=0.040) and CAD-noAS cohorts (HR 2.29, 95%CI 1.22-4.30, p=0.010). The 1-year rate of MACCE was similar between TAVI-noCAD and CAD-noAS patients (9.8% vs. 9.5%, HR 1.05, 95%CI 0.59-1.87, p=0.86). CONCLUSIONS Concomitant CAD in the setting of TAVI conveyed an increased risk of ischemic events and cardiovascular mortality at 1-year follow-up.

Incidence and impact of renal dysfunction on clinical outcomes after transcatheter aortic valve implantation

BACKGROUND The impact of baseline renal dysfunction on early and late clinical outcomes after transcatheter aortic valve implantation (TAVI) remains to be defined. METHODS 927 patients included in the prospective Bern TAVI registry were classified on the basis of the baseline estimated glomerular filtration rate (eGFR), as having none or mild (eGFR ≥60mL/min/1.73m2, n=284, 30.6%), moderate (eGFR between 30 and 59mL/min/1.73m2, n=535, 57.7%) and severe (eGFR <30mL/min/1.73m2, n=108, 11.7%) renal dysfunction. RESULTS A graded relationship between stages of renal dysfunction and increasing risk profile was observed with higher STS score and lower left ventricular ejection fraction among patients with eGFR<30 (p<0.001 across groups). In patients with none or mild, moderate, and severe renal dysfunction the rate of all-cause mortality was 1.8%, 5.2% and 8.3% at 30-day and 11.0%, 15.0% and 19.5% at 1-year, respectively. After adjusting for relevant confounders, severe renal dysfunction was associated with an increased risk of cardiovascular death (adjusted Hazard Ratio, HRadj, 3.90, 95% Confidence Interval, CI 1.15-13.2) and stage 3 acute kidney injury (HRadj 5.15, 95% CI 1.72-15.5) at 30-day follow-up, however no significant association was found for clinical outcomes at 1-year follow-up. Moreover, moderate and severe renal dysfunction were found to be associated with bleeding at 1-year follow-up (HRadj, 1.36, 95% CI 1.04-1.78 and HRadj 1.49, 95% CI 1.00-2.21, respectively). CONCLUSIONS Pre-procedural renal dysfunction differentially affects early clinical outcomes, although the magnitude of this association is diluted over time by the overriding effect of underlying risk and comorbidities.

New-onset arrhythmias following transcatheter aortic valve implantation: a systematic review and meta-analysis

Objective To evaluate the prevalence and clinical impact of new-onset arrhythmias in patients following transcatheter aortic valve implantation (TAVI). Method We systematically identified studies reporting new-onset arrhythmias after TAVI other than atrioventricular conduction disturbances. We summarised monitoring strategies, type and prevalence of arrhythmias and estimated their effect on risk of death or cerebrovascular events by using random-effects meta-analysis. The study is registered withInternational prospective register of systematic reviews (PROSPERO) (CRD42017058053). Results Sixty-five studies (43 506 patients) reported new-onset arrhythmias following TAVI. The method of arrhythmia detection was specified only in 31 studies (48%). New-onset atrial fibrillation (NOAF) (2641 patients), bradyarrhythmias (182 patients), supraventricular arrhythmias (29 patients), ventricular arrhythmias (28 patients) and non-specified major arrhythmias (855 patients) were reported. In most studies (52 out of 65), new-onset arrhythmia detection was limited to the first month following TAVI. The most frequently documented arrhythmia was NOAF with trend of increasing summary prevalence of 11%, 14%, 14% and 25% during inhospital, 30-day, 1-year and 2-year follow-ups, respectively (P for trend=0.011). Summary prevalence estimates of NOAF at 30-day follow-up differ significantly between studies of prospective and retrospective design (8% and 21%, respectively, P=0.002). New episodes of bradyarrhythmias were documented with a summary crude prevalence of 4% at 1-year follow-up. NOAF increased the risk of death (relative risk 1.61, 95% CI 1.35 to 1.98, I2=47%) and cerebrovascular events (1.79, 95% CI 1.24 to 2.64, I2=0%). No study commented on therapeutic modifications following the detection of new-onset arrhythmias. Conclusions Systematic identification of new-onset arrhythmias following TAVI may have considerable impact on subsequent therapeutic management and long-term prognosis in this patient population.

Early Detection of Subclinical Myocardial Damage in Chronic Aortic Regurgitation and Strategies for Timely Treatment of Asymptomatic Patients

A series of hemodynamic and pathological responses occur in chronic aortic regurgitation, which eventually result in myocardial fibrosis and irreversible left ventricular dysfunction. According to guidelines, valvular surgery is recommended with the development of symptoms, left ventricular systolic dysfunction, or left ventricular dilatation. The optimal timing of surgical intervention has recently been questioned with documentation of irreversible myocardial damage resulting in incomplete left ventricular recovery and adverse clinical outcomes after surgery. Recognizing the shortcomings of the guidelines, we performed a comprehensive review on the novel diagnostic methods that have been shown to improve the detection of subclinical ventricular dysfunction in chronic aortic regurgitation and to improve prediction of outcomes.