Routine 4D Cardiac CT to Identify Concomitant Transthyretin Amyloid Cardiomyopathy in Older Adults with Severe Aortic Stenosis.

Background Transthyretin amyloid cardiomyopathy (ATTR-CM) often coexists with severe aortic stenosis (AS). Although strain analysis from cardiac MRI and echocardiography was demonstrated to predict coexisting ATTR-CM, comparable data from four-dimensional (4D) cardiac CT are lacking despite wide availability. Purpose To evaluate the diagnostic performance of 4D cardiac CT-derived parameters in identifying ATTR-CM in older adults considered for transcatheter aortic valve implantation (TAVI). Materials and Methods This prospective single-center screening study for ATTR-CM included consecutive patients with severe AS considered for TAVI who underwent 4D cardiac CT between August 2019 and August 2021 approximately 1 day before technetium 99m (99mTc) 3,3-diphosphono-1,2-propanodicarboxylic-acid (DPD) scintigraphy. The diagnostic performance of CT-based left ventricular (LV), right ventricular, and left atrial dimensions, ejection fraction (EF), and myocardial strain were evaluated against 99mTc-DPD scintigraphy as the reference standard to identify ATTR-CM. Predictors and an unweighted cardiac CT score were validated with internal bootstrapping. The assignment of variables to the score was based on cutoff values achieving the highest Youden index J. Results Among 263 participants (mean age, 83 years ± 4.6 [SD]; 149 male and 114 female participants), 99mTc-DPD scintigraphy (Perugini grade 2 or 3) confirmed coexisting ATTR-CM in 27 (10.3%). CT-derived LV mass index, LV and LA global longitudinal strain (GLS), and relative apical longitudinal strain each predicted the presence of ATTR-CM with an area under the curve (AUC) of at least 0.70. Implementing these parameters with cutoff values of 81 g/m2 or higher, -14.9% or higher, less than 11.5%, and 1.7 or higher in the CT score, respectively, yielded high diagnostic performance (AUC = 0.89; 95% CI: 0.81, 0.94; P < .001) robust to internal bootstrapping validation (AUC = 0.88; 95% CI: 0.82, 0.94). If two criteria were fulfilled, the sensitivity and specificity in the detection of ATTR-CM were 96.3% (95% CI: 81.0, 99.9) and 58.9% (95% CI: 52.3, 65.2), respectively. Conclusion When compared against 99mTc-DPD scintigraphy as the reference standard, routine 4D cardiac CT in older adults considered for TAVI provided high diagnostic performance in the detection of concomitant ATTR-CM by assessing LV and left atrial GLS, relative apical longitudinal strain, and LV mass index. ClinicalTrials.gov registration no.: NCT04061213 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Tavakoli and Onder in this issue.

Amyloid Transthyretin Cardiomyopathy in Elderly Patients With Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation.

Background The prevalence of calcific aortic stenosis and amyloid transthyretin cardiomyopathy (ATTR-CM) increase with age, and they often coexist. The objective was to determine the prevalence of ATTR-CM in patients with severe aortic stenosis and evaluate differences in presentations and outcomes of patients with concomitant ATTR-CM undergoing transcatheter aortic valve implantation. Methods and Results Prospective screening for ATTR-CM with Technetium99-3,3-diphosphono-1,2-propanodicarboxylic acid bone scintigraphy was performed in 315 patients referred with severe aortic stenosis between August 2019 and August 2021. Myocardial Technetium99-3,3-diphosphono-1,2-propanodicarboxylic acid tracer uptake was detected in 34 patients (10.8%), leading to a diagnosis of ATTR-CM in 30 patients (Perugini ≥2: 9.5%). Age (85.7±4.9 versus 82.8±4.5; P=0.001), male sex (82.4% versus 57.7%; P=0.005), and prior carpal tunnel surgery (17.6% versus 4.3%; P=0.007) were associated with coexisting ATTR-CM, as were ECG (discordant QRS voltage to left ventricular wall thickness [42% versus 12%; P<0.001]), echocardiographic (left ventricular ejection fraction 48.8±12.8 versus 58.4±10.8; P<0.001; left ventricular mass index, 144.4±45.8 versus 117.2±34.4g/m2; P<0.001), and hemodynamic parameters (mean aortic valve gradient, 23.4±12.6 versus 35.5±16.6; P<0.001; mean pulmonary artery pressure, 29.5±9.7 versus 25.8±9.5; P=0.037). Periprocedural (cardiovascular death: hazard ratio [HR], 0.71 [95% CI, 0.04-12.53]; stroke: HR, 0.46 [95% CI, 0.03-7.77]; pacemaker implantation: HR, 1.54 [95% CI, 0.69-3.43]) and 1-year clinical outcomes (cardiovascular death: HR, 1.04 [95% CI, 0.37-2.96]; stroke: HR, 0.34 [95% CI, 0.02-5.63]; pacemaker implantation: HR, 1.50 [95% CI, 0.67-3.34]) were similar between groups. Conclusions Coexisting ATTR-CM was observed in every 10th elderly patient with severe aortic stenosis referred for therapy. While patients with coexisting pathologies differ in clinical presentation and echocardiographic and hemodynamic parameters, peri-interventional risk and early clinical outcomes were comparable up to 1 year after transcatheter aortic valve implantation. REGISTRATION URL: https://www.clinicaltrials.gov. Unique identifier: NCT04061213.

Association of atrial fibrillation with survival in patients with low-flow low-gradient aortic stenosis with preserved ejection fraction undergoing TAVI.

AIMS: There is limited evidence on the prognostic significance of atrial fibrillation (AF) in patients with low flow, low gradient aortic stenosis with preserved ejection fraction (LFLG-pEF AS). We aimed to evaluate the recovery of stroke volume after transcatheter aortic valve implantation (TAVI) and clinical outcomes in patients with LFLG-pEF AS stratified by presence or absence of AF. METHODS AND RESULTS: In a prospective TAVI registry, patients with preserved left ventricular ejection fraction (LVEF ≥ 50%) were stratified according to flow-gradient status and presence of AF. Among 2 259 TAVI patients with preserved LVEF between August 2007 and June 2021, 765 had high-gradient AS (HG AS) and 444 had LFLG-pEF AS. AF was observed in 199 patients with HG AS (26.0%) and 190 patients with LFLG-pEF AS (42.8%). At 1 year, SVi was significantly improved in LFLG-pEF AS patients without AF, while SVi remained low in patients with AF (from 25.9 ± 8.5 mL/m2 to 37.2 ± 9.9 mL/m2 and from 26.8 ± 5.1 mL/m2 to 26.1 ± 9.1 mL/m2, respectively). LFLG-pEF AS patients with AF had an increased risk of 1-year all-cause mortality compared with those without AF (HRadjusted 2.57; 95% CI 1.44-4.59). LFLG-pEF AS patients without AF had similar mortality compared with HG AS patients without AF (HRadjusted 0.85; 95% CI 0.49-1.46). CONCLUSIONS: Patients with LFLG-pEF AS and AF experienced no relevant recovery of stroke volume after TAVI, but a more than two-fold increased risk of death compared to patients with HG AS or LFLG-pEF AS without AF. Clinical Trial Registration: https://www.clinicaltrials.gov. NCT01368250.

Risk and Timing of Noncardiac Surgery After Transcatheter Aortic Valve Implantation.

Importance: Noncardiac surgery after transcatheter aortic valve implantation (TAVI) is a clinical challenge with concerns about safety and optimal management. Objectives: To evaluate perioperative risk of adverse events associated with noncardiac surgery after TAVI by timing of surgery, type of surgery, and TAVI valve performance. Design, Setting, and Participants: This cohort study was conducted using data from a prospective TAVI registry of patients at the tertiary care University Hospital in Bern, Switzerland. All patients undergoing noncardiac surgery after TAVI were identified. Data were analyzed from November through December 2021. Exposures: Timing, clinical urgency, and risk category of noncardiac surgery were assessed among patients who had undergone TAVI and subsequent noncardiac surgery. Main Outcomes and Measures: A composite of death, stroke, myocardial infarction, and major or life-threatening bleeding within 30 days after noncardiac surgery. Results: Among 2238 patients undergoing TAVI between 2013 and 2020, 300 patients (mean [SD] age, 81.8 [6.6] years; 144 [48.0%] women) underwent elective (160 patients) or urgent (140 patients) noncardiac surgery after TAVI and were included in the analysis. Of these individuals, 63 patients (21.0%) had noncardiac surgery within 30 days of TAVI. Procedures were categorized into low-risk (21 patients), intermediate-risk (190 patients), and high-risk (89 patients) surgery. Composite end points occurred within 30 days of surgery among 58 patients (Kaplan-Meier estimate, 19.7%; 95% CI, 15.6%-24.7%). There were no significant differences in baseline demographics between patients with the 30-day composite end point and 242 patients without this end point, including mean (SD) age (81.3 [7.1] years vs 81.9 [6.5] years; P = .28) and sex (25 [43.1%] women vs 119 [49.2%] women; P = .37). Timing (ie, ≤30 days from TAVI to noncardiac surgery), urgency, and risk category of surgery were not associated with increased risk of the end point. Moderate or severe prosthesis-patient mismatch (adjusted hazard ratio [aHR], 2.33; 95% CI, 1.37-3.95; P = .002) and moderate or severe paravalvular regurgitation (aHR, 3.61; 95% CI 1.25-10.41; P = .02) were independently associated with increased risk of the end point. Conclusions and Relevance: These findings suggest that noncardiac surgery may be performed early after successful TAVI. Suboptimal device performance, such as prosthesis-patient mismatch and paravalvular regurgitation, was associated with increased risk of adverse outcomes after noncardiac surgery.

Diagnostic performance of quantitative coronary artery disease assessment using computed tomography in patients with aortic stenosis undergoing transcatheter aortic-valve implantation.

BACKGROUND: Computed tomography angiography (CTA) is a cornerstone in the pre- transcatheter aortic valve replacement (TAVI) assessment. We evaluated the diagnostic performance of CTA and coronary artery calcium score (CACS) for CAD evaluation compared to invasive coronary angiography in a cohort of TAVI patients. METHODS: In consecutive TAVI patients without prior coronary revascularization and device implants, CAD was assessment by quantitative analysis in CTA. (a) Patients with non-evaluable segments were classified as obstructive CAD. (b) In patients with non-evaluable segments a CACS cut-off of 100 was applied for obstructive CAD. The reference standard was quantitative invasive coronary angiography (QCA, i.e. ≥ 50% stenosis). RESULTS: 100 consecutive patients were retrospectively included, age was 82.3 ± 6.5 years and 30% of patients had CAD. In 16% of the patients, adequate visualization of the entire coronary tree (all 16 segments) was possible with CTA, while 84% had at least one segment which was not evaluable for CAD analysis due to impaired image quality. On a per-patient analysis, where patients with low image quality were classified as CAD, CTA showed a sensitivity of 100% (95% CI 88.4-100.0), specificity of 11.4% (95% CI 5.1-21.3), PPV of 32.6% (95% CI 30.8-34.5), NPV of 100% and diagnostic accuracy of 38% (95% CI 28.5-48.3) for obstructive CAD. When applying a combined approach of CTA (in patients with good image quality) and CACS (in patients with low image quality), the sensitivity and NPV remained at 100% and obstructive CAD could be ruled out in 20% of the TAVI patients, versus 8% using CTA alone. CONCLUSION: In routinely acquired pre-TAVI CTA, the image quality was insufficient in a high proportion of patients for the assessment of the entire coronary artery tree. However, when adding CACS in patients with low image quality to quantitative CTA assessment in patients with good image quality, obstructive CAD could be ruled-out in 1/5 of the patients and may therefore constitute a strategy to streamline pre-procedural workup, and reduce risk, radiation and costs in selected TAVI patients without prior coronary revascularization or device implants.

Effect of Timing of Staged Percutaneous Coronary Intervention on Clinical Outcomes in Patients With Acute Coronary Syndromes.

Background Complete revascularization reduces cardiovascular events in patients with acute coronary syndromes (ACSs) and multivessel disease. The optimal time point of non-target-vessel percutaneous coronary intervention (PCI) remains a matter of debate. The aim of this study was to investigate the impact of early (<4 weeks) versus late (≥4 weeks) staged PCI of non-target-vessels in patients with ACS scheduled for staged PCI after hospital discharge. Methods and Results All patients with ACS undergoing planned staged PCI from 2009 to 2017 at Bern University Hospital, Switzerland, were analyzed. Patients with cardiogenic shock, in-hospital staged PCI, staged cardiac surgery, and multiple staged PCIs were excluded. The primary end point was all-cause death, recurrent myocardial infarction and urgent premature non-target-vessel PCI. Of 8657 patients with ACS, staged revascularization was planned in 1764 patients, of whom 1432 patients fulfilled the eligibility criteria. At 1 year, there were no significant differences in the crude or adjusted rates of the primary end point (7.8% early versus 10.8% late, hazard ratio [HR], 0.72 [95% CI, 0.47-1.10], P=0.129; adjusted HR, 0.80 [95% CI, 0.50-1.28], P=0.346) and its individual components (all-cause death: 1.5% versus 2.9%, HR, 0.52 [95% CI, 0.20-1.33], P=0.170; adjusted HR, 0.62 [95% CI, 0.23-1.67], P=0.343; recurrent myocardial infarction: 4.2% versus 4.4%, HR, 0.97 [95% CI, 0.475-1.10], P=0.924; adjusted HR, 1.03 [95% CI, 0.53-2.01], P=0.935; non-target-vessel PCI, 3.9% versus 5.7%, HR, 0.97 [95% CI, 0.53-1.80], P=0.928; adjusted HR, 1.19 [95% CI, 0.61-2.34], P=0.609). Conclusions In this single-center cohort study of patients with ACS scheduled to undergo staged PCI after hospital discharge, early (<4 weeks) versus late (≥4 weeks) staged PCI was associated with a similar rate of major adverse cardiac events at 1 year follow-up. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02241291.

Validation of high bleeding risk criteria and definition as proposed by the academic research consortium for high bleeding risk.

AIMS: To validate the set of clinical and biochemical criteria proposed by consensus by the Academic Research Consortium (ARC) for High Bleeding Risk (HBR) for the identification of HBR patients. These criteria were categorized into major and minor, if expected to carry in isolation, respectively, ≥4% and <4% Bleeding Academic Research Consortium (BARC) 3 or 5 bleeding risk within 1-year after percutaneous coronary intervention (PCI). High bleeding risk patients are those meeting at least 1 major or 2 minor criteria. METHODS AND RESULTS: All patients undergoing PCI at Bern University Hospital, between February 2009 and September 2018 were prospectively entered into the Bern PCI Registry (NCT02241291). Age, haemoglobin, platelet count, creatinine, and use of oral anticoagulation were prospectively collected, while the remaining HBR criteria except for planned surgery were retrospectively adjudicated. A total of 16 580 participants with complete ARC-HBR criteria were included. After assigning 1 point to each major and 0.5 point to each minor criterion, we observed for every 0.5 score increase a step-wise augmentation of BARC 3 or 5 bleeding rates at 1 year ranging from 1.90% among patients fulfilling no criterion, through 4.01%, 5.98%, 7.42%, 8.60%, 12.21%, 12.29%, and 17.64%. All major and five out of six minor criteria, conferred in isolation a risk for BARC 3 or 5 bleeding at 1 year exceeding 4% at the upper limit of the 95% confidence intervals. CONCLUSION: All major and the majority of minor ARC-HBR criteria identify in isolation patients at HBR.

Impact of Left Ventricular Outflow Tract Calcification on Procedural Outcomes After Transcatheter Aortic Valve Replacement.

OBJECTIVES: This study aimed to systematically assess the importance of left ventricular outflow tract (LVOT) calcification on procedural outcomes and device performances with contemporary transcatheter heart valve (THV) systems. BACKGROUND: LVOT calcification has been associated with adverse clinical outcomes after transcatheter aortic valve replacement (TAVR). However, the available evidence is limited to observational data with modest numbers and incomplete assessment of the effect of the different THV systems. METHODS: In a retrospective analysis of a prospective single-center registry, LVOT calcification was assessed in a semiquantitative fashion. Moderate or severe LVOT calcification was documented in the presence of 2 nodules of calcification, or 1 extending >5 mm in any direction, or covering >10 % of the perimeter of the LVOT. RESULTS: Among 1,635 patients undergoing TAVR between 2007 and 2018, moderate or severe LVOT calcification was found in 407 (24.9%). Patients with moderate or severe LVOT calcification had significantly higher incidences of annular rupture (2.3% vs. 0.2%; p < 0.001), bailout valve-in-valve implantation (2.9% vs. 0.8%; p = 0.004), and residual aortic regurgitation (11.1% vs. 6.3%; p = 0.002). Balloon-expandable valves conferred a higher risk of annular rupture in the presence of moderate or severe LVOT calcification (4.0% vs. 0.4%; p = 0.002) as compared with the other valve designs. There was no significant interaction of valve design or generation and LVOT calcification with regard to the occurrence of bailout valve-in-valve implantation and residual aortic regurgitation. CONCLUSIONS: Moderate or severe LVOT calcification confers increased risks of annular rupture, residual aortic regurgitation, and implantation of a second valve. The risk of residual aortic regurgitation is consistent across valve designs and generations. (SWISS TAVI Registry; NCT01368250).

Feasibility and safety of transcaval transcatheter aortic valve implantation: a multicentre European registry.

AIMS: A transfemoral transarterial approach is considered the preferable access route for transcatheter aortic valve implantation (TAVI), followed by a transaxillary/subclavian TAVI approach. However, these approaches may not be an option in all patients. This study aimed to report the initial European experience with transfemoral transcaval TAVI. METHODS AND RESULTS: Data on 50 patients treated by transcaval TAVI in five European centres were collected and analysed according to the Valve Academic Research Consortium (VARC)-2 definitions. The study population had a mean age of 78.7±8.0 years and a high surgical risk profile (median STS risk score 6.1%, interquartile range 3.0-11.2%). Transcaval access was successful in 49 out of 50 patients and device success was obtained in 94% of cases. Closure of the caval-aortic puncture site with a nitinol cardiac occluder was successful in all cases without need for emergent surgery. One patient received additional sealing of the aortic puncture site with a covered stent one day post TAVI due to a gradual haemoglobin drop of 3 g/dL. VARC-2-defined life-threatening bleeding and major vascular complications possibly related to transcaval access were 4% and 10%, respectively. There were no bleeding or vascular complications after discharge. At 30 days, the clinical efficacy endpoint was reached in 88% of patients. CONCLUSIONS: Transfemoral transcaval access proved to be a feasible and safe TAVI approach for high-risk patients with severe aortic stenosis not suitable for transfemoral or transaxillary/subclavian transarterial access.

Five-Year Outcomes in Patients With Diabetes Mellitus Treated With Biodegradable Polymer Sirolimus-Eluting Stents Versus Durable Polymer Everolimus-Eluting Stents.

Background The choice of optimal drug-eluting stent therapy for patients with diabetes mellitus (DM) undergoing percutaneous coronary intervention remains uncertain. We aimed to assess the long-term clinical outcomes after percutaneous coronary intervention with biodegradable polymer sirolimus-eluting stents (BP-SES) versus durable polymer everolimus-eluting stents (DP-EES) in patients with DM. Methods and Results In a prespecified subgroup analysis of the BIOSCIENCE (Ultrathin Strut Biodegradable Polymer Sirolimus-Eluting Stent Versus Durable Polymer Everolimus-Eluting Stent for Percutaneous Coronary Revascularization) trial (NCT01443104), patients randomly assigned to ultrathin-strut BP-SES or thin-strut DP-EES were stratified according to diabetic status. The primary end point was target lesion failure, a composite of cardiac death, target vessel myocardial infarction, and clinically indicated target lesion revascularization, at 5 years. Among 2119 patients, 486 (22.9%) presented with DM. Compared with individuals without DM, patients with DM were older and had a greater baseline cardiac risk profile. In patients with DM, target lesion failure at 5 years occurred in 74 patients (cumulative incidence, 31.0%) treated with BP-SES and 57 patients (25.8%) treated with DP-EES (risk ratio, 1.23; 95% CI, 0.87-1.73 [P=0.24]). In individuals without DM, target lesion failure at 5 years occurred in 124 patients (16.8%) treated with BP-SES and 132 patients (16.8%) treated with DP-EES (risk ratio, 0.98; 95% CI, 0.77-1.26 [P=0.90; P for interaction=0.31]). Cumulative 5-year incidence rates of cardiac death, target vessel myocardial infarction, clinically indicated target lesion revascularization, and definite stent thrombosis were similar among patients with DM treated with BP-SES or DP-EES. There was no interaction between diabetic status and treatment effect of BP-SES versus DP-EES. Conclusions In a prespecified subgroup analysis of the BIOSCIENCE trial, we found no difference in clinical outcomes throughout 5 years between patients with DM treated with ultrathin-strut BP-SES or thin-strut DP-EES. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT01443104.

Mechanical complications in patients with ST-segment elevation myocardial infarction: A single centre experience.

BACKGROUND: The study aims to assess characteristics and outcomes of patients suffering a mechanical complication (MC) after ST-segment elevation myocardial infarction (STEMI) in a contemporary cohort of patients in the percutaneous coronary intervention era. METHODS AND RESULTS: This retrospective single-center cohort study encompasses 2508 patients admitted with STEMI between March 9, 2009 and June 30, 2014. A total of 26 patients (1.1%) suffered a mechanical complication: ventricular septal rupture (VSR) in 17, ventricular free wall rupture (VFWR) in 2, a combination of VSD and VFWR in 2, and papillary muscle rupture (PMR) in 5 patients. Older age (74.5 ± 10.4 years versus 63.9 ± 13.1 years, p < 0.001), female sex (42.3% versus 23.3%, p = 0.034), and a longer latency period between symptom onset and angiography (> 24h: 42.3% versus 16.2%, p = 0.002) were more frequent among patients with MC as compared to patients without MC. The majority of MC patients had multivessel disease (77%) and presented in cardiogenic shock (Killip class IV: 73.1%). Nine patients (7 VSR, 2 VFWR & VSR) were treated conservatively and died. Out of the remaining 10 VSR patients, four underwent surgery, three underwent implantation of an occluder device, and another three patients had surgical repair following occluder device implantation. All patients with isolated VFWR and PMR underwent emergency surgery. At 30 days, mortality for VSR, VFWR, VFWR & VSR and PMR amounted to 71%, 50%, 100% and 0%, respectively. CONCLUSIONS: Despite advances in the management of STEMI patients, mortality of mechanical complications stays considerable in this contemporary cohort. Older age, female sex, and a prolonged latency period between symptom onset and angiography are associated with the occurrence of these complications.

Current state of alternative access for transcatheter aortic valve implantation.

The transfemoral (TF) route constitutes the undisputed default access for transcatheter aortic valve implantation (TAVI). In patients in whom anatomical constraints preclude a TF approach, several alternative access routes have been used. Transthoracic (transapical and transaortic) access routes show higher mortality and bleeding complication rates than the TF approach, which is attributable to the higher baseline risk of the selected patients and the more invasive nature of these procedures. Alternative transarterial approaches (transaxillary, transcarotid, transinnominate) have demonstrated high technical success rates and a favourable safety profile in selected patients and are particularly valuable in the presence of poor respiratory function or previous cardiothoracic surgery. The transcaval approach is an innovative fully percutaneous approach that allows the introduction of large-bore sheaths and shows promising results in high-risk patients. Diligent procedural planning, appropriate patient selection and the expertise of the Heart Team allow the achievement of an adequate safety and efficacy profile of TAVI performed via alternative access. Future studies incorporating standardised and independent outcome assessment are required to gain further knowledge on the risk/benefit relation pertaining to the specific approaches and improve selection of the appropriate access route for the individual patient.

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.

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)-1ß, 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.