Nurse-led sedation for transfemoral transcatheter aortic valve implantation seems safe for a selected patient population.

Transcatheter aortic valve implantation (TAVI) has become a high-volume procedure with increasing demands on hospital resources. Local anaesthesia with sedation supervised by an anaesthesiology team is the current standard of care. We aimed to describe our experience with a simplified, nurse-led sedation (NLS) protocol. This study enrolled 128 consecutive patients who underwent transfemoral TAVI with self-expandable Evolut R prosthesis between November 2019 and April 2021. Operators selected 50% of patients for NLS based on the clinical expectation of lower risk of procedural difficulties. Nurse-led sedation protocol demanded only mild to moderate levels of sedation. The clinical outcomes were determined from the local TAVI registry and the national mortality database. Baseline patient characteristics were similar in the NLS (n = 64) and anaesthesiologist-led sedation (ALS) (n = 64) groups except higher prevalence of diabetes mellitus (48.4% vs. 31.3%, P = 0.035) and peripheral vascular disease (20.3% vs. 7.8%, P = 0.036) in the ALS group. There was a trend for the larger prostheses used in the ALS group (P = 0.058). The procedural results did not differ, and coronary care team backup was rarely needed in the NLS group (6% of patients). The in-hospital outcomes were identical from both clinical and echocardiography perspectives, and 30-day mortality was low in both groups (1.5%). For the NLS group, preparation in the catheterization laboratory was quicker by 6.4 min (P = 0.01), and intensive care unit stay was shorter (2.03 vs. 3.48 days, P = 0.001). In conclusion, the NLS for the selected transfemoral TAVI population seems safe.

Burn-Induced Cardiac Dysfunction: A Brief Review and Long-Term Consequences for Cardiologists in Clinical Practice.

BACKGROUND: Severe burn injury is a specific type of trauma, which induces a unique complex of responses in the body and leads to an extreme increase in stress hormones and proinflammatory cytokines. These hypermetabolic and stress responses are desirable in the acute phase but can persist for several years and lead - due to several mechanisms - to many late complications, including myocardial dysfunction. METHODS: The databases of PubMed, ScienceDirect, National Institutes of Health (NIH) of the United States, and Google Scholar were searched. Studies relevant to the topic of late cardiovascular dysfunction after burn injury were compiled using key words. RESULTS: Burn-induced heart disease significantly increases morbidity and mortality and contributes to the reduction in the quality of life of patients after severe burn trauma. A variety of mechanisms causing myocardial dysfunction after burn trauma have been detailed but understanding all of the exact consequences is limited, especially regarding chronic cardiovascular changes. CONCLUSION: A detailed understanding of the pathophysiology of chronic cardiac changes can contribute to a comprehensive and preventive treatment plan and improve long-term outcomes of burn patients.

Intravascular haemolysis after transcatheter aortic valve implantation with self-expandable prosthesis: incidence, severity, and impact on long-term mortality.

We aimed to determine the incidence, severity, and long-term impact of intravascular haemolysis after self-expanding transcatheter aortic valve implantation (TAVI). We believe this should be evaluated before extending the indications of TAVI to younger low-risk patients. Prospective, academic, single centre study of 94 consecutive patients treated with supra-annular self-expandable TAVI prosthesis between April 2009 and January 2014. Haemolysis at 1-year post-TAVI was defined per the published criteria based on levels of haemoglobin, reticulocyte and schistocyte count, lactate dehydrogenase (LDH), and haptoglobin. All patients had long-term clinical follow-up (6 years). The incidence of haemolysis at 1-year follow-up varied between 9% and 28%, based on different haemolysis definitions. Haemolysis was mild in all cases, no patient had markedly increased LDH levels. The presence of moderate/severe paravalvular aortic regurgitation was associated with haemolysis (7.7% vs. 23.1%, P = 0.044) and aortic valve area post-TAVI did not differ between groups with or without haemolysis (1.01 vs. 0.92 cm2/m2, P = 0.23) (definition including schistocyte count). The presence of haemolysis did not have any impact on patient prognosis after 6 years with log-rank test P = 0.80. Intravascular haemolysis after TAVI with self-expandable prosthesis is present in 9-28% of patients depending on the definition of haemolysis. The presence of haemolysis is associated with moderate/severe paravalvular aortic regurgitation but not with post-TAVI aortic valve area. Haemolysis is mild with no impact on prognosis.

Clinical and laboratory predictors of Infectious Complications in patients after Out-of-Hospital Cardiac Arrest.

PURPOSE: Identification of clinical and laboratory predictors related to Infectious Complications (ICs) in patients after Out-of-Hospital Cardiac Arrest (OHCA). METHODS: Patients, aged >18, after an OHCA between 9/2013 and 11/2015, surviving >24h, were studied. RESULTS: Study group consisted of 42 patients (mean age 63.4years, 88.1% men). Forty percent of patients had IC; lower respiratory tract infections were most common (87.5% of cases). ICs were more common in patients receiving Targeted Temperature Management (50% vs. 10%; p=0.032). Antibiotics were used in 85.7% of patients. The mean time to therapy initiation was 9.6 (SD 7.1) hours after admission. The mean course of treatment was 9.0 (SD 6.2) days. Fifty-three percent of patients receiving early antibiotic treatment didn't have IC. Initial antibiotic therapy was changed more often in patients with IC (75% vs. 38.9%; p=0.045). C-Reactive Protein, Procalcitonin, Troponin and White Blood Cell count values were higher in patients with IC. CONCLUSION: Early initiated antibiotic treatment is overused in patients after OHCA. This practice is associated with necessitating antibiotic change in the majority of patients with IC. Assessment of clinical and laboratory parameters in the first days after OHCA increases the likelihood of appropriate ATB therapy.

Characteristics and Survival Determinants in Patients After Out-of-Hospital Cardiac Arrest in The Era of 24/7 Coronary Intervention Facilities.

BACKGROUND: Survival rates and outcomes after out-of-hospital cardiac arrest (OHCA) remain low despite investments of time and money. The goal of this analysis was to identify variables related to survival of patients transferred to our coronary care unit (CCU) after an OHCA. METHODS: 102 consecutive OHCA patients, mean age 64.6 (SD 13.3), 70.6% men, between January, 2011 and December, 2013, who were transferred to our tertiary care CCU, were studied. RESULTS: Cardiac-cause OHCA was present in 84 patients (82.4%). Of these 60.7% had an acute coronary syndrome (ACS) - STEMI 35.7%; NSTEMI 23.8%. Coronary angiography was performed in 73 (71.6%) patients - 81% with cardiac- and 31.3% (5/16) with a non-cardiac cause. Percutaneous coronary intervention (PCI) was performed in 50 patients (68.5%), 49 with cardiac-cause, and succeeded in 92%. In-hospital mortality was 38.2%, one-year mortality was 51.5%. In-hospital and one-year mortality were related to age (p=0.002 resp. p=0.001), first ECG rhythm (p=0.001, resp. p=0.005), history of coronary artery disease (RR 2.1; p=0.026 resp. RR 1.71; p=0.029), and history of arrhythmia (supraventricular tachyarrhythmia, bradyarrhythmia) (RR 2.74; p=0.003 resp. RR 2.3; p=0.001). One-year mortality was also related to a history of diabetes mellitus (RR 1.89; p=0.006). CONCLUSION: Cardiac-cause was the most common cause of OHCA. Acute coronary syndrome was present in more than half of the cases. Availability of interventional facilities was a crucial factor in OHCA management. A history of coronary artery disease, diabetes mellitus, and arrhythmia were associated with worse survival.

Renal denervation in comparison with intensified pharmacotherapy in true resistant hypertension: 2-year outcomes of randomized PRAGUE-15 study.

OBJECTIVES: The randomized, multicentre study compared the efficacy of renal denervation (RDN) versus spironolactone addition in patients with true resistant hypertension. We present the 24-month data. METHODS: A total of 106 patients with true resistant hypertension were enrolled in this study: 52 patients were randomized to RDN and 54 patients to the spironolactone addition, with baseline SBP of 159 ±â€Š17 and 155 ±â€Š17 mmHg and average number of drugs 5.1 and 5.4, respectively. Two-year data are available in 86 patients. Spironolactone addition, as crossover after 1 year, was performed in 23 patients after RDN, and spironolactone addition followed by RDN was performed in five patients. RESULTS: Similar and comparable reduction of 24-h SBP after RDN or spironolactone addition after randomization was observed, 9.1 mmHg (P = 0.001) and 10.9 mmHg (P = 0.001), respectively. Similar decrease of office blood pressure (BP) was observed, 17.7 mmHg (P < 0.001) versus 14.1 mmHg (P < 0.001), whereas the number of antihypertensive drugs did not differ significantly between groups. Crossover analysis showed nonsignificantly better efficacy of spironolactone addition in 24-h SBP and office SBP reduction than RDN (3.7 mmHg, P = 0.27 and 4.6 mmHg, P = 0.28 in favour of spironolactone addition, respectively). Meanwhile, the number of antihypertensive drugs was significantly increased after spironolactone addition (+0.7, P = 0.001). CONCLUSION: In the settings of true resistant hypertension, spironolactone addition (if tolerated) seems to be of better efficacy than RDN in BP reduction over a period of 24 months. However, by contrast to the 12-month results, BP changes were not significantly greater.

Degenerative changes and immune response after transcatheter aortic valve implantation. Comparison with surgical aortic valve replacement.

BACKGROUND: Little is known about the valve degeneration process after transcutaneous aortic valve implantations (TAVI) that can have an important impact on patients' long-term prognosis. AIM: To evaluate degenerative changes of TAVI using computed tomography (CT) compared to findings in patients that underwent surgical aortic valve replacement (SAVR). Subsequently, to compare the level of immune and inflammatory markers in both groups and test their possible role in the valve degeneration process. METHODS AND RESULTS: 49 patients after TAVI and 29 patients in the control group after SAVR underwent 2 years of follow-up and 8 patients from the TAVI group and 7 patients after SAVR underwent five years of follow-up. CT was performed in all patients and calcifications on prosthesis cusps in both groups were measured using Agatson calcium score. TAVI patients were older compared to patients who underwent SAVR [82 (62;86) vs. 74 (64;84) years, p<0.001], and had more comorbidities - higher EuroScore I [21.0 (5.0;46.0) vs. 6.15 (2.54;11.17), p<0.001]. TAVI patients had more often concomitant coronary artery disease (69.4% vs. 13.8%, p<0.001) and previous history of cardiac surgery (32.7% vs. 0.0%, p<0.001). Slight calcifications (mean Agatson score 50.76) on prosthetic cusps were found in 2 patients 4-5 years after TAVI and in 1 patient 2 years after SAVR (p=NS). Even though significant differences were found in values of tumor necrosis factor-α and E-selectin before, 1 year, and 2 years after implantation, no significant changes in values of inflammatory markers were observed during follow-up period in both groups of patients. Detailed analysis revealed no significant difference between values of inflammatory markers of patients with and without calcifications present on CT. CONCLUSION: Minimal degenerative changes on TAVI prosthesis were observed in mid- and long-term follow-up. Systemic immune response did not differ between patients after TAVI and SAVR.

Invasive Hemodynamic Assessment of Cardiac Output State after MitraClip Therapy in Nonanaesthetized Patients with Functional Mitral Regurgitation.

Background. Surgical correction of mitral regurgitation (MR) can lead to postoperative low cardiac output state. We aimed to assess the acute hemodynamic changes after percutaneous MitraClip therapy (a unique model without influence of factors linked to surgical procedure) in patients with functional MR without the influence of general anaesthesia. Methods. We studied invasive hemodynamic parameters in 23 patients before procedure (conscious, nonsedated patients), during procedure (intubated patients), and the first day after MitraClip implantation (conscious, extubated patients). Results. Mitral valve clipping significantly increased cardiac index (CI) (from 2.0 ± 0.5 to 3.3 ± 0.6 L/min/m2; p < 0.01). Conversely, there was significant reduction in the mean pulmonary capillary wedge pressure (PCWP) (from 18.6 ± 5.7 to 10.5 ± 3.8 mmHg; p < 0.01), mean pulmonary artery pressure (from 29.8 ± 10.9 to 25.2 ± 10.3 mmHg; p = 0.03), and pulmonary vascular resistance index (from 531 ± 359 to 365 ± 193 dyn·s·cm-5/m2; p = 0.03). Conclusions. The functional MR therapy with percutaneous MitraClip device results in significant increase in CI (+66%) and concomitant decrease in PCWP (-42%). None of our patients developed low cardiac output state. Our results support the idea that significant part of low cardiac output state after cardiac surgery is due to surgery related factors rather than due to increase in afterload after MR elimination.

Role of Adding Spironolactone and Renal Denervation in True Resistant Hypertension: One-Year Outcomes of Randomized PRAGUE-15 Study.

This randomized, multicenter study compared the relative efficacy of renal denervation (RDN) versus pharmacotherapy alone in patients with true resistant hypertension and assessed the effect of spironolactone addition. We present here the 12-month data. A total of 106 patients with true resistant hypertension were enrolled in this study: 52 patients were randomized to RDN and 54 patients to the spironolactone addition, with baseline systolic blood pressure of 159±17 and 155±17 mm Hg and average number of drugs 5.1 and 5.4, respectively. Twelve-month results are available in 101 patients. The intention-to-treat analysis found a comparable mean 24-hour systolic blood pressure decline of 6.4 mm Hg, P=0.001 in RDN versus 8.2 mm Hg, P=0.002 in the pharmacotherapy group. Per-protocol analysis revealed a significant difference of 24-hour systolic blood pressure decline between complete RDN (6.3 mm Hg, P=0.004) and the subgroup where spironolactone was added, and this continued within the 12 months (15 mm Hg, P= 0.003). Renal artery computed tomography angiograms before and after 1 year post-RDN did not reveal any relevant changes. This study shows that over a period of 12 months, RDN is safe, with no serious side effects and no major changes in the renal arteries. RDN in the settings of true resistant hypertension with confirmed compliance is not superior to intensified pharmacological treatment. Spironolactone addition (if tolerated) seems to be more effective in blood pressure reduction.

Antiplatelet efficacy of P2Y12 inhibitors (prasugrel, ticagrelor, clopidogrel) in patients treated with mild therapeutic hypothermia after cardiac arrest due to acute myocardial infarction.

Survivors after cardiac arrest (CA) due to AMI undergo PCI and then receive dual antiplatelet therapy. Mild therapeutic hypothermia (MTH) is recommended for unconscious patients after CA to improve neurological outcomes. MTH can attenuate the effectiveness of P2Y12 inhibitors by reducing gastrointestinal absorption and metabolic activation. The combined effect of these conditions on the efficacy of P2Y12 inhibitors is unknown. We compared the antiplatelet efficacies of new P2Y12 inhibitors in AMI patients after CA treated with MTH. Forty patients after CA for AMI treated with MTH and received one P2Y12 inhibitor (clopidogrel, prasugrel or ticagrelor) were enrolled in a prospective observational single-center study. Platelet inhibition was measured by VASP (PRI) on days 1, 2, and 3 after drug administration. In-hospital clinical data and 1-year survival data were obtained. The proportion of patients with ineffective platelet inhibition (PRI > 50 %, high on-treatment platelet reactivity) for clopidogrel, prasugrel, and ticagrelor was 77 vs. 19 vs. 1 % on day 1; 77 vs. 17 vs. 0 % on day 2; and 85 vs. 6 vs. 0 % on day 3 (P < 0.001). The platelet inhibition was significantly worse in clopidogrel group than in prasugrel or ticagrelor group. Prasugrel and ticagrelor are very effective for platelet inhibition in patients treated with MTH after CA due to AMI, but clopidogrel is not. Using prasugrel or ticagrelor seems to be a more suitable option in this high-risk group of acute patients.

Selection of P2Y12 antagonist, treatment initiation, and predictors of high on-treatment platelet reactivity in a "Real World" registry.

OBJECTIVE: The present study aimed to compare characteristics related to selection of a P2Y12 antagonist, investigate initiation of therapy with new-generation drugs, and identify predictors of high on-treatment platelet reactivity (HTPR) in patients with acute coronary syndrome treated with stent percutaneous coronary intervention (PCI). METHODS AND RESULTS: Data from 589 patients in the LAPCOR (Laboratory AntiPlatelet efficacy and Clinical Outcome Registry; ClinicalTrials.gov Identifier: NCT02264912) registry was analyzed. P2Y12 receptor antagonist efficacy was measured by VASP phosphorylation 24 ± 4 hours after a loading dose of clopidogrel (600 mg, N=407), prasugrel (60 mg, N=106), or ticagrelor (180 mg, N=76) and expressed by platelet reactivity index (PRI). HTPR was defined as PRI ≥50%. Patients treated with prasugrel were significantly younger and had significantly higher hemoglobin levels than those who received clopidogrel or ticagrelor, while chronic kidney disease was significantly more prevalent in the ticagrelor group. Almost all invasively managed patients given new-generation drugs received a loading dose after coronary angiography. Mean residual PRI and HTPR were significantly higher after clopidogrel (44.2 ± 23.1% and 42.2%, respectively) vs. prasugrel (17.7 ± 18.0% and 9.4%, respectively) or ticagrelor (18.8 ± 17.0% and 7.9%, respectively; all p<0.001). Among multiple variables tested, HTPR in patients treated with the new agents significantly related only to platelet count (p=0.014) and mean platelet volume (p=0.03). CONCLUSION: Safety is the most important aspect under consideration in choosing new agents for an individual patient. Other than platelet count and mean platelet volume, factors known as predictors of higher platelet reactivity, did not influence the efficacy of new-generation P2Y12 receptor antagonists.

Randomized comparison of renal denervation versus intensified pharmacotherapy including spironolactone in true-resistant hypertension: six-month results from the Prague-15 study.

This prospective, randomized, open-label multicenter trial evaluated the efficacy of catheter-based renal denervation (Symplicity, Medtronic) versus intensified pharmacological treatment including spironolactone (if tolerated) in patients with true-resistant hypertension. This was confirmed by 24-hour ambulatory blood pressure monitoring after excluding secondary hypertension and confirmation of adherence to therapy by measurement of plasma antihypertensive drug levels before enrollment. One-hundred six patients were randomized to renal denervation (n=52), or intensified pharmacological treatment (n=54) with baseline systolic blood pressure of 159±17 and 155±17 mm Hg and average number of drugs 5.1 and 5.4, respectively. A significant reduction in 24-hour average systolic blood pressure after 6 months (-8.6 [95% cofidence interval: -11.8, -5.3] mm Hg; P<0.001 in renal denervation versus -8.1 [95% cofidence interval: -12.7, -3.4] mm Hg; P=0.001 in pharmacological group) was observed, which was comparable in both groups. Similarly, a significant reduction in systolic office blood pressure (-12.4 [95% cofidence interval: -17.0, -7.8] mm Hg; P<0.001 in renal denervation versus -14.3 [95% cofidence interval: -19.7, -8.9] mm Hg; P<0.001 in pharmacological group) was present. Between-group differences in change were not significant. The average number of antihypertensive drugs used after 6 months was significantly higher in the pharmacological group (+0.3 drugs; P<0.001). A significant increase in serum creatinine and a parallel decrease of creatinine clearance were observed in the pharmacological group; between-group difference were borderline significant. The 6-month results of this study confirmed the safety of renal denervation. In conclusion, renal denervation achieved reduction of blood pressure comparable with intensified pharmacotherapy.

Pharmacodynamic effect of clopidogrel in patients undergoing transcatheter aortic valve implantation.

The aim of this study was to analyze periprocedural and mid-term effect of clopidogrel on platelet function using the VerifyNow P2Y12 point-of-care assay in patients undergoing TAVI. Platelet reactivity was measured at the beginning of the procedure after 300 mg clopidogrel bolus administration and during the follow-up (at 1 month after the procedure) in 52 patients undergoing TAVI using the Medtronic CoreValve prosthesis (Medtronic CoreValve). A cutoff value of 240 PRU was used to identify nonresponders to clopidogrel treatment with high residual platelet reactivity (HRPR). Baseline HRPR was identified in 80% of patients and in 72% of patients during 6-month follow-up. There was no significant difference in the pharmacodynamic effects of clopidogrel on platelet reactivity from baseline to 6-months follow-up (297 ± 57 vs. 275 ± 62; P = 0.058). Ischemic event occurred only in 3 patients (5.8%) from the study group. In conclusion, majority of patients undergoing TAVI had high residual platelet reactivity after pretreatment with 300 mg of clopidogrel and during the 6-month follow-up at dual antiplatelet treatment. The noneffectiveness of clopidogrel in the TAVI population raises the question of the routine use of dual antiplatelet treatment in this setting.

Lack of association between clopidogrel responsiveness tested using point-of-care assay and prognosis of patients with coronary artery disease.

Dual antiplatelet therapy is important treatment modality across the spectrum of coronary artery disease manifestations. However, a significant number of patients do not have a completely effective response to clopidogrel. This study assessed the impact of response after clopidogrel with Verify Now device on prognosis on patients undergoing coronary interventions. Consecutive patients following percutaneous coronary intervention were prospectively enrolled. A loading dose of 600 mg of clopidogrel was administered before or during PCI. Blood samples were drawn within 24 h after clopidogrel administration. The effect of clopidogrel was measured using VerifyNow. All patients were evaluated at 6 months. The primary end-point was the combination of death, MI and stroke. 378 patients (69.3 % men and 30.7 % women) were enrolled. The mean age was 67.2 ± 12.8 years, BMI 28.9 ± 17.7, and 116 patients had diabetes (30.7 %). During the 6-months follow-up 30 patients (7.94 %) experienced a monitored end-point: 12 patients (3.17 %) had MI; five patients (1.32 %) strokes and 15 patients (3.97 %) died. The remaining 248 patients (71.26 %) were end-point free. Factors associated with a poor prognosis were: leukocytes (OR 1.7 [1.2-2.4], p < 0.01), creatinine (OR 1.4 [1.1-2.5], p < 0.05) and at a borderline level the presence of AA allele of gene CYP2C19*2 (OR 2.5 [0.99-4.1], p = 0.052). The results using VerifyNow were similar between both groups (Group End-point: 208.5 ± 85.5, group No end-point 203.1 ± 91.3) and failed to show any prognostic value (OR 1.00 [0.992-1.007], p = 0.9). The measurement of clopidogrel efficacy using VerifyNow had no prognostic value for our unselected cohort of patients after PCI.

The purification step is not crucial in EIA measurements of thromboxane B2 and 11-dehydrothromboxane B2 in human plasma.

BACKGROUND: Thromboxane B2 (TxB2) and particularly 11-dehydrothromboxane B2 (11-dTxB2) are widely used as prognostic risk markers of platelet activation in cardiovascular diseases. The main errors in TxB2 and 11-dTxB2 determination include either low concentrations of circulating TxB2 (1 - 2 pg/mL) and 11-dTxB2 (0.9 - 4.3 pg/mL) or rather high transiency (mean TxB2 half-life is approximately 5 minutes) as well as an incorrect pre-analytical phase set up. The aim of this study was to investigate the impact of a widely used purification step on the results of enzyme immunosorbent assay (EIA)--based measurement of the two selected thromboxanes. METHODS: For the purpose of this study, 20 plasma samples (10 healthy donors, 10 patients under treatment with acetylsalicylic acid) were screened for TxB2 and 11-dTxB2 concentrations using commercial competitive EIA kits (Cayman Chemicals, Tallinn, Estonia; Neogen, Lexington, KY, USA) with or without the introduction of the purification procedure. RESULTS: The purification step does not significantly affect the results of EIA measurements of the two of TxA2 metabolites (TxB2, 11-dTxB2) in human plasma. The levels of TxB2 and 11-dTxB2 determined in the plasma samples were not significantly changed (p < 0.05) when the purification step was omitted compared to the purified samples. CONCLUSIONS: This study establishes a protocol allowing for reliable and reproducible plasma TxB2 and 11-dTxB2 EIA measurement for routine basic screening of platelet function.

Evaluation of aspirin's effect on platelet function early after coronary artery bypass grafting.

OBJECTIVE: Aspirin therapy decreases mortality and ischemic complication rates after coronary artery bypass grafting (CABG). However, platelet inhibition after oral aspirin seems to be insufficient in the early postoperative period. There are incomplete data reporting aspirin efficacy early after CABG. The aim of this study was to assess the pharmacologic effect of aspirin on platelets in the first postoperative days using the most specific laboratory tests for the evaluation of aspirin efficacy. DESIGN: A prospective study. SETTING: A clinical study in one cardiac surgery center and measurements in two pharmacologic institutions. PARTICIPANTS: Thirty patients. INTERVENTIONS: Postoperative aspirin efficacy (200 mg/d) was assessed by the suppression of serum thromboxane B(2) (TxB(2)) and by arachidonic acid-induced aggregometry using the MULTIPLATE analyzer. Samples were collected before surgery and on postoperative days 1-5. METHODS AND MAIN RESULTS: The median baseline value (range) of serum TxB(2) was 1.6 ng/mL (1.4-1.9). The median TxB(2) inhibition >90% (the value required for full platelet inhibition) was not achieved until day 5 (-91%, 0.13 ng/mL [0.08-0.22], p < 0.001) and in only 55% of patients. The median baseline ASPI value was 805 (640-975) aggregation units (AU)*min. A significant decrease in aspirin insufficiency was not seen before postoperative day 5 (390 [243-621], p < 0.003) and only 34% of patients reached an effective platelet inhibition on day 5 (cutoff < 300 AU*min). CONCLUSIONS: The effect of aspirin on inhibition of TxB(2) production and arachidonic acid-induced platelet aggregation is impaired during the first postoperative days after CABG. A more effective antiplatelet strategy presumably could increase early graft patency and improve clinical outcomes after CABG.

Aspirin is insufficient in inhibition of platelet aggregation and thromboxane formation early after coronary artery bypass surgery.

BACKGROUND: Aspirin administered early after coronary artery bypass grafting surgery (CABG) improves graft patency and patients survival. However, the antiplatelet effect of aspirin seems to be variable and aspirin resistance is currently still being discussed. The aim of the study was to assess aspirin efficacy in the early postoperative period. METHODS: Forty patients undergoing elective CABG surgery (20 in on-pump and 20 in off-pump) were enrolled in the study. Functional and biochemical responses to aspirin were evaluated by arachidonic acid (ARA)-induced platelet aggregation and urine 11-dehydro Thromboxane B2 metabolite excretion. Samples were collected before surgery (baseline; > or =7 days after aspirin withdrawal) and on days 1, 2 and 5 after surgery. RESULTS: Median baseline ARA aggregability was 55%. On day 1, platelet aggregability decreased (12%, P < 0.001). On day 2, despite the aspirin administration, platelet aggregability exceeded the values from day 1 (38%, P < 0.001). Only on day 5, sufficient inhibition of platelet aggregation was achieved (8%, P < 0.001). Median preoperative urine concentration of 11-dehydroTxB2 was 106 ng/mmol of creatinine. On day 1, the concentration decreased only slightly and insignificantly (97 ng/ml, P = NS), similarly as on day 2 (86 ng/ml, P = NS). Only on day 5, significant decrease in concentration of thromboxane metabolite was achieved compared to preoperative values (46 ng/ml, P = 0.001). CONCLUSION: Aspirin did not sufficiently inhibit platelet aggregation and thromboxane formation in the early postoperative period. Thus, antiplatelet treatment strategy should be intensified or modified in patients early after bypass surgery.

Higher platelet activity is present in patients with restenosis after percutaneous coronary intervention compared with patients with an occlusion of coronary artery bypass graft.

The aim of the study was to compare platelet activity between patients with an occlusion of bypass graft after coronary artery bypass graft surgery and restenosis after percutaneous coronary intervention (PCI); that is, between patients with reappearance of ischemia after two different kinds of coronary revascularization. Thirty patients were studied in a cross-sectional designed study. Fifteen of them were patients with the worst bypass graft patency from Prague-4 study (control protocol-driven coronary angiography performed at 1 year after surgery; originally 47 bypass grafts implanted, 94% of venous grafts occluded). The remaining 15 were patients with restenosis 3-12 months after PCI. Blood samples were drawn at least 12 weeks after coronary angiography. Platelet activity was determined by membrane expression of P-selectin (CD62P, % of positive cells) by flow cytometry, aggregability by ADP aggregometry. Data are expressed as mean +/- SEM. Both groups were similar with respect to age, BMI and presence of diabetes mellitus. No patient suffered from acute coronary syndrome. P-selectin expression was significantly higher in the patients with restenosis compared with patients with bypass graft occlusion (1.96 +/- 0.07 vs. 0.77 +/- 0.03, P < 0.001, Wilcoxon test). ADP aggregometry was not different between groups (55.5 +/- 1.1 vs. 56.1 +/- 0.8, P = NS). Higher platelet activity is present in the patients with restenosis after PCI compared with the patients with the occlusion of bypass graft. Platelet activity play more important role in the development of restenosis after PCI compared with the occlusion of bypass graft after coronary artery bypass graft surgery, at least in the period up to 1 year after revascularization.

Platelet activity and aspirin efficacy after off-pump compared with on-pump coronary artery bypass surgery: results from the prospective randomized trial PRAGUE 11-Coronary Artery Bypass and REactivity of Thrombocytes (CABARET).

OBJECTIVES: Changes in hemostasis after off-pump coronary artery bypass grafting are still being discussed. There is a lack of information about platelet activity and aspirin efficacy after coronary artery bypass grafting. The aim of this study was to assess and compare platelet activity and aspirin efficacy early and late after off-pump and on-pump coronary artery bypass grafting. METHODS: Eighty patients were enrolled in a prospective randomized study. Platelet activity was determined based on membrane expression of antigen CD62P (P-selectin) by means of flow cytometric analysis. Aspirin efficacy was assessed by using arachidonic acid-induced platelet aggregation. Blood samples were collected before the operation, immediately postoperatively, and on days 1, 2, 5, and 30. RESULTS: In the off-pump group expression of P-selectin was markedly increased in comparison with preoperative values, with a maximum difference observed on day 2 (+53%, P = .02), and it was significantly higher compared with that seen in the on-pump group on days 2 and 5 (+53% vs +4%, P = .004, and +20% vs -16%, P = .005). On day 30, P-selectin expression was similar both between the groups and in comparison with the preoperative values. Arachidonic acid-induced platelet aggregation was gradually decreasing until day 30, but on day 2, there was an unexpected increase in aggregation that was more expressed in the off-pump group. CONCLUSIONS: The platelet activity is higher in the early postoperative period in off-pump compared with on-pump coronary artery bypass grafting. The present aspirin strategy seems to be insufficient in the early postoperative period, irrespective of the surgical technique used.

Off-pump versus on-pump coronary artery surgery.

The aim of this preliminary, prospective, randomized study was to compare rotation thromboelastography (roTEG) results and D-dimer levels in off-pump versus on-pump coronary surgery in order to identify the activation of fibrinolysis. Twenty patients scheduled for coronary bypass grafting were assessed (off-pump group A, n = 10; on-pump group B, n = 10). Blood samples for roTEG examination were taken preoperatively (t0), 15 minutes after sternotomy (t1), on the completion of peripheral bypass anastomoses (t2), and at the end of procedures (t3). The time points for D-dimer levels analyses were before operation, at the end of procedures, and 24 hours later. A certain degree of roTEG signs of fibrinolysis was noticed at time t2 in both groups and in group B these marks were quite widely, but not significantly expressed (P for intergroup differences for Lysis on Set Time at 60 and 150 minutes were P = 0.190 and P = 0.122, respectively), borderline differences were found for Maximum Clot Firmness (P = 0.082) with a lower mean value for group B (arithmetic means [95% confidence intervals]--57.7 [54.2; 61.2] mm). Completely expressed roTEG signs of hyperfibrinolysis were observed in 2 patients from group B. In group B also the highest geometric means of D-dimers (1326.0 [943.5; 1863.6] ng mL(-1)) and thus a dramatic intergroup difference (P < 0.001) were observed at the end of surgery; 24 hours later the significantly elevated D-dimer levels in both groups (A: 1070.0 [723.5; 1582.6] versus B: 1093.3 [732.0; 1632.9] ng mL(-1)) were equalized (P = 0.932). Our roTEG results display a slightly greater, but fairly subtle activation of fibrinolysis during the course of cardiopulmonary bypass, compared to off-pump cardiac surgery.