TransCatheter aortic valve implantation and fractional flow reserve-guided percutaneous coronary intervention versus conventional surgical aortic valve replacement and coronary bypass grafting for treatment of patients with aortic valve stenosis and multivessel or advanced coronary disease: The transcatheter valve and vessels trial (TCW trial): Design and rationale.

BACKGROUND: Patients with severe aortic stenosis (AS) frequently present with concomitant obstructive coronary artery disease (CAD). In those, current guidelines recommend combined coronary artery bypass grafting (CABG) and surgical aortic valve replacement (SAVR) as the preferred treatment option, although this surgical approach is associated with a high rate of clinical events. Combined transcatheter aortic valve implantation (TAVI) and percutaneous coronary intervention (PCI) with or without FFR have evolved as a valid alternative for cardiac surgery in patients with AS and multivessel or advanced CAD. To date, no dedicated trial has prospectively evaluated the outcomes of a percutaneous versus surgical treatment for patients with both severe AS and CAD. AIMS: To investigate whether fractional-flow reserve (FFR)-guided PCI and TAVI is noninferior to combined CABG and SAVR for the treatment of severe AS and multivessel or advanced CAD. METHODS: The Transcatheter Valve and Vessels (TCW) trial (clinicaltrial.gov: NCT03424941) is a prospective, randomized, controlled, open label, international trial. Patients ≥ 70 years with severe AS and multivessel (≥ 2 vessels) or advanced CAD, deemed feasible by the heart team for both; a full percutaneous or surgical treatment, will be randomised in a 1:1 fashion to either FFR-guided PCI followed by TAVI (intervention arm) vs. CABG and SAVR (control arm). The primary endpoint is a patient-oriented composite of all-cause mortality, myocardial infarction, disabling stroke, unscheduled clinically-driven target vessel revascularization, valve reintervention, and life threatening or disabling bleeding at 1 year. The TCW trial is powered for noninferiority, and if met, superiority will be tested. Assuming a primary endpoint rate of 30% in the CABG-SAVR arm, with a significance level α of 5%, a noninferiority limit delta of 15% and a loss to follow-up of 2%, a total of 328 patients are needed to obtain a power of 90%. The primary endpoint analysis is performed on an intention-to-treat basis. SUMMARY: The TCW Trial is the first prospective randomized trial that will study if a less invasive percutaneous treatment for severe AS and concomitant advanced CAD (i.e., FFR-guided PCI-TAVI) is noninferior to the guidelines recommended approach (CABG-SAVR).

Differential biomarker expression in heart failure patients with and without mitral regurgitation: Insights from BIOSTAT-CHF.

BACKGROUND: Mitral regurgitation (MR) frequently coexists with heart failure (HF). OBJECTIVES: To better understand potential pathophysiological differences between patients with HF with or without moderate-severe MR, we compared differentially expressed circulating biomarkers between these two groups. METHODS: The Olink Proteomics® Multiplex Cardiovascular (CVD) -II, CVD-III, Immune Response and Oncology-II panels of 363 unique proteins from different pathophysiological domains were used to investigate the biomarker profiles of HF patients from index and validation cohorts of the BIOSTAT-CHF study stratified according to the presence of moderate-to-severe MR or no-mild MR. RESULTS: The index cohort included 888 patients (46%) with moderate-to-severe MR and 1029 (54%) with no-mild MR at baseline. The validation cohort included 522 patients (33%) with moderate-to-severe MR and 1076 (66%) with no-mild MR at baseline. Compared to patients with no-mild MR, those with moderate-to-severe MR had lower body mass index, higher comorbidity burden, signs and symptoms of more severe HF, lower systolic blood pressure, and larger left atrial and ventricular dimensions, in both cohorts. NT-proBNP, CA125, fibroblast growth factor 23 (FGF23) and growth hormone 1 (GH1) were up-regulated, whereas leptin (LEP) was down-regulated in patients with moderate-severe MR versus no-mild MR, in both index and validation cohorts. CONCLUSION: Circulating biomarkers differently expressed in HF patients with moderate-severe MR versus no-mild MR were related to congestion, lipid and mineral metabolism and oxidative stress. These findings may be of value for the development of novel treatment targets in HF patients with MR.

Changes in Right Ventricular-to-Pulmonary Artery Coupling After Transcatheter Edge-to-Edge Repair in Secondary Mitral Regurgitation.

BACKGROUND: Preprocedural right ventricular-to-pulmonary artery (RV-PA) coupling is a major predictor of outcome in patients with secondary mitral regurgitation (SMR) undergoing transcatheter edge-to-edge mitral valve repair (M-TEER). However, clinical significance of changes in RV-PA coupling after M-TEER is unknown. OBJECTIVES: The aim of this study was to evaluate changes in RV-PA coupling after M-TEER, their prognostic value, and predictors of improvement. METHODS: This was a retrospective observational study, including patients undergoing successful M-TEER (residual mitral regurgitation ≤2+ at discharge) for SMR at 13 European centers and with complete echocardiographic data at baseline and short-term follow-up (30-180 days). RV-PA coupling was assessed with the use of echocardiography as the ratio of tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP). All-cause death was assessed at the longest available follow-up starting from the time of the echocardiographic reassessment. RESULTS: Among 501 patients included, 331 (66%) improved their TAPSE/PASP after M-TEER (responders) at short-term follow-up (median: 89 days; IQR: 43-159 days), whereas 170 (34%) did not (nonresponders). Lack of previous cardiac surgery, low postprocedural mitral mean gradient, low baseline TAPSE, high baseline PASP, and baseline tricuspid regurgitation were independently associated with TAPSE/PASP improvement after M-TEER. Compared with nonresponders, responders had lower New York Heart Association functional class and less heart failure hospitalizations at short-term follow-up. Improvement in TAPSE/PASP was independently associated with reduced risk of mortality at long-term follow-up (584 days; IQR: 191-1,243 days) (HR: 0.65 [95% CI: 0.42-0.92]; P = 0.017). CONCLUSIONS: In patients with SMR, improvement in TAPSE/PASP after successful M-TEER is predicted by baseline clinical and echocardiographic variables and postprocedural mitral gradient, and is associated with a better outcome.

Transcatheter edge-to-edge repair of tricuspid regurgitation in the Netherlands: state of the art and future perspectives.

Despite the high prevalence and adverse clinical outcomes of severe tricuspid regurgitation (TR), conventional treatment options, surgical or pharmacological, are limited. Surgery is associated with a high peri-operative risk and medical treatment has not clearly resulted in clinical improvements. Therefore, there is a high unmet need to reduce morbidity and mortality in patients with severe TR. During recent years, several transcatheter solutions have been studied. This review focuses on the transcatheter edge-to-edge repair of TR (TTVR) with respect to patient selection, the procedure, pre- and peri-procedural echocardiographic assessments and clinical outcomes. Furthermore, we highlight the current status of TTVR in the Netherlands and provide data from our initial experience at the University Medical Centre Groningen.

Sex-Based Differences in Unrecognized Myocardial Infarction.

Background Myocardial infarction is an important cause of morbidity and mortality in both men and women. Atypical or the absence of symptoms, more prevalent among women, may contribute to unrecognized myocardial infarctions and missed opportunities for preventive therapies. The aim of this research is to investigate sex-based differences of undiagnosed myocardial infarction in the general population. Methods and Results In the Lifelines Cohort Study, all individuals ≥18 years with a normal baseline ECG were followed from baseline visit till first follow-up visit (≈5 years, n=97 203). Individuals with infarct-related changes between baseline and follow-up ECGs were identified. The age- and sex-specific incidence rates were calculated and sex-specific cardiac symptoms and predictors of unrecognized myocardial infarction were determined. Follow-up ECG was available after a median of 3.8 (25th and 75th percentile: 3.0-4.6) years. During follow-up, 198 women experienced myocardial infarction (incidence rate 1.92 per 1000 persons-years) compared with 365 men (incidence rate 3.30; P<0.001 versus women). In 59 (30%) women, myocardial infarction was unrecognized compared with 60 (16%) men (P<0.001 versus women). Individuals with unrecognized myocardial infarction less often reported specific cardiac symptoms compared with individuals with recognized myocardial infarction. Predictors of unrecognized myocardial infarction were mainly hypertension, smoking, and higher blood glucose level. Conclusions A substantial proportion of myocardial infarctions are unrecognized, especially in women. Opportunities for secondary preventive therapies remain underutilized if myocardial infarction is unrecognized.

Plasma interleukin 6 levels are associated with cardiac function after ST-elevation myocardial infarction.

BACKGROUND AND AIMS: Myocardial infarction triggers an inflammatory response involved in cardiac repair. We studied the association of the interleukin 6 (IL-6) cascade with infarct size and cardiac function after ST-elevation myocardial infarction (STEMI). METHODS: In 369 STEMI patients IL-6, soluble IL-6 receptor (sIL-6R), and soluble glycoprotein (sgp) 130 were measured at baseline (hospital admission), 24 h, 2 weeks, 7 weeks, 4 months, and 1 year post-PCI and sIL-6R/IL-6 ratio was calculated. At 4 months, infarct size and left ventricular ejection fraction (LVEF) were assessed by magnetic resonance imaging. Diastolic function (E/e') was determined by echocardiography. RESULTS: Hospital admission levels for IL-6, sIL-6R, sgp 130 were 3.7 pg/ml (IQR 2.1-6.7 pg/ml), 51.6 ng/ml (IQR 37.3-69.0 ng/ml), and 332 ng/ml (IQR 280-399 ng/ml), respectively. 24 h after admission, IL-6 had increased threefold compared to baseline (p < 0.001) and returned below baseline (p < 0.001) 2 weeks after STEMI. sIL-6R and sgp130 levels at 24 h remained similar to baseline but were increased at 2 weeks (p < 0.001; p < 0.001, respectively). IL-6 and sIL-6R/IL-6 ratio at 24 h were independently associated with infarct size [ß 5.4 (95% CI 3.3-7.5); p < 0.001, ß - 4.0 (95% CI - 6.1 to - 1.9); p < 0.001, respectively]. Higher levels of IL-6 at 24 h were associated with lower LVEF [ß - 4.2 (95% CI -6.7 to - 1.8); p = 0.001]. CONCLUSIONS: Higher IL-6 and lower sIL-6R/IL-6 ratio early after presentation with STEMI are indicative for larger infarct size and decreased cardiac function at 4 months.

Early Intravenous Beta-Blockers in Patients With ST-Segment Elevation Myocardial Infarction Before Primary Percutaneous Coronary Intervention.

BACKGROUND: The impact of intravenous (IV) beta-blockers before primary percutaneous coronary intervention (PPCI) on infarct size and clinical outcomes is not well established. OBJECTIVES: This study sought to conduct the first double-blind, placebo-controlled international multicenter study testing the effect of early IV beta-blockers before PPCI in a general ST-segment elevation myocardial infarction (STEMI) population. METHODS: STEMI patients presenting <12 h from symptom onset in Killip class I to II without atrioventricular block were randomized 1:1 to IV metoprolol (2 × 5-mg bolus) or matched placebo before PPCI. Primary endpoint was myocardial infarct size as assessed by cardiac magnetic resonance imaging (CMR) at 30 days. Secondary endpoints were enzymatic infarct size and incidence of ventricular arrhythmias. Safety endpoints included symptomatic bradycardia, symptomatic hypotension, and cardiogenic shock. RESULTS: A total of 683 patients (mean age 62 ± 12 years; 75% male) were randomized to metoprolol (n = 336) or placebo (n = 346). CMR was performed in 342 patients (54.8%). Infarct size (percent of left ventricle [LV]) by CMR did not differ between the metoprolol (15.3 ± 11.0%) and placebo groups (14.9 ± 11.5%; p = 0.616). Peak and area under the creatine kinase curve did not differ between both groups. LV ejection fraction by CMR was 51.0 ± 10.9% in the metoprolol group and 51.6 ± 10.8% in the placebo group (p = 0.68). The incidence of malignant arrhythmias was 3.6% in the metoprolol group versus 6.9% in placebo (p = 0.050). The incidence of adverse events was not different between groups. CONCLUSIONS: In a nonrestricted STEMI population, early intravenous metoprolol before PPCI was not associated with a reduction in infarct size. Metoprolol reduced the incidence of malignant arrhythmias in the acute phase and was not associated with an increase in adverse events. (Early-Beta blocker Administration before reperfusion primary PCI in patients with ST-elevation Myocardial Infarction [EARLY-BAMI]; EudraCT no: 2010-023394-19).

Safety and clinical outcome of erythropoiesis-stimulating agents in patients with ST-elevation myocardial infarction: a meta-analysis of individual patient data.

BACKGROUND: Erythropoiesis-stimulating agents (ESAs) have been investigated in small studies in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). Erythropoiesis-stimulating agents did not show a clear effect on left ventricular function or clinical outcome, but some studies suggested an increased risk of thromboembolic events. METHODS: A systematic literature search in MEDLINE was performed, until December 2012. We included randomized clinical trials investigating the effect of ESAs in STEMI patients undergoing primary PCI, with ≥30 days of follow-up. The primary end point was a composite of all-cause mortality, myocardial infarction, and stent thrombosis after PCI. Secondary end point was all-cause mortality. RESULTS: Individual patient data were obtained from 10 of 11 trials, including 97.3% (1,242/1,277) of all patients randomized to control (n = 600) or to ESAs (n = 642). Baseline characteristics were well balanced between the treatment allocations. Mean follow-up time was 248 (±131) days. The primary end point occurred in 3.5% (20/577) in the control group and in 2.1% (13/610) in the ESA group (hazard ratio for ESAs, 0.63; 95% CI [0.31-1.27]; P = .20). Mortality occurred in 13 (2.3%) in the control group and 5 (0.8%) in the ESA group (hazard ratio for ESAs, 0.38; 95% CI [0.13-1.06]; P = .06). CONCLUSIONS: Erythropoiesis-stimulating agent administration does not result in an increased risk of adverse cardiac events in STEMI patients undergoing primary PCI. Results of ongoing studies may provide further insight to the potential beneficial clinical effects of ESAs in STEMI patients.

Erythropoiesis-stimulating agents and heart failure.

Anemia is a common comorbidity in heart failure (HF) patients. Its occurrence and severity are associated with worse prognosis. Although the etiology of anemia is multifactorial, inappropriate erythropoietin (EPO) production and/or bone-marrow resistance to EPO appear crucial in majority of anemic HF patients. Consequently, treatment based on this pathophysiological background may prove to be most effective and beneficial. In a number of smaller clinical studies, administration of erythropoiesis-stimulating agents (ESAs) to anemic HF patients improved a number of surrogate endpoints, including left ventricular function, exercise capacity, renal function, and different quality of life parameters. However, two larger, phase II studies, did not fully confirm these promising results. Furthermore, many concerns have been raised on the safety of ESAs after the recent publication of studies correcting anemia in patients with chronic kidney disease (CKD). On the other hand, chronic HF population varies significantly from CKD patients, with different comorbidities, renal function, and etiology of anemia. Moreover, ESAs have been shown to possess robust nonhematopoietic effects in the heart, namely inhibition of apoptosis and stimulation of neovascularization. Therefore, large-scale trials with ESAs are required to examine the effect and safety of anemia treatment in HF patients.

Erythropoiesis stimulation in acute ischemic syndromes.

Erythropoietin (EPO) is a hematopoietic hormone with extensive nonhematopoietic properties. The discovery of an EPO receptor outside the hematopoietic system has fuelled research into the beneficial effects of EPO for various conditions, predominantly in cardiovascular disease. Experimental evidence has revealed the cytoprotective properties of EPO, and it seems that the EPO-EPO receptor system provides a powerful backbone against acute myocardial ischemia, gaining from the different properties of EPO. There is an ongoing discussion about possible discrepancy between preclinical and clinical effects of EPO on the cardiovascular system. Large, randomized, placebo-controlled clinical trials are underway to give a final verdict on EPO treatment for acute coronary syndromes.

Anemia and erythropoietin in heart failure.

Anemia is frequently observed in patients with chronic heart failure (CHF) and is related to an impaired outcome. The origin of anemia in CHF is diverse and is associated with several factors including renal failure, resistance of the bone marrow to erythropoietin (EPO), hematinic deficiencies, and medication use. Recently, several small-scale clinical trials have shown that EPO treatment might improve clinical parameters in anemic heart failure patients. In addition, several preclinical studies have shown that EPO possesses non-hematopoietic effects. This current review focuses on the etiology, consequences, and treatment of anemia in heart failure patients. The pleiotropic effects of EPO in an experimental setting will also be discussed. Heart Fail Monit 2008;6(1):28-33.

Low-dose erythropoietin improves cardiac function in experimental heart failure without increasing haematocrit.

BACKGROUND: Erythropoietin (EPO) may improve cardiac function and induce neovascularisation in experimental models of chronic heart failure (CHF). However, the increased haematocrit associated with EPO treatment might exert concomitant deleterious effects. AIM: To investigate the haematocrit independent effects of EPO on cardiac function. METHODS AND RESULTS: Rats underwent permanent coronary artery ligation to induce myocardial infarction (MI) or sham surgery. Three weeks after MI, rats were randomly allocated to treatment with vehicle (MI) or the long-acting EPO analogue darbepoetin alfa administered in a high (40 microg/kg/3 weeks, MI-EPO-high) or a low-dose (0.4 microg/kg/3 weeks, MI-EPO-low). After 9 weeks, haemodynamic parameters, myocardial histology and Myosin Heavy Chain (MHC) isoforms were determined. High-dose EPO resulted in a significant increase in haematocrit (p<0.01) while low-dose EPO had no effect on haematocrit levels. EPO significantly improved cardiac function in both EPO groups, reflected by increased left ventricular (LV)-developed pressure and improved contractility (dP/dt(max)) and relaxation (dP/dt(min)) indices of the LV at 9-weeks (all p<0.05 compared to MI). The improved cardiac function was associated with increased capillary growth (38% in MI-EPO-high (p<0.01) and 27% in MI-EPO-low (p<0.05)) and an attenuated switch to slow beta-MHC isoforms in both EPO groups. CONCLUSIONS: EPO improves cardiac function and induces neovascularisation at a dose that does not increase haematocrit, thereby circumventing the possible deleterious effects of increased erythropoiesis.

Erythropoietin improves cardiac function through endothelial progenitor cell and vascular endothelial growth factor mediated neovascularization.

AIMS: Erythropoietin (EPO) improves cardiac function and induces neovascularization in chronic heart failure (CHF), although the exact mechanism has not been elucidated. We studied the effects of EPO on homing and incorporation of endothelial progenitor cells (EPC) into the myocardial microvasculature and myocardial expression of angiogenic factors. METHODS AND RESULTS: CHF was induced in rats by coronary artery ligation resulting in myocardial infarction (MI) after bone marrow had been replaced by human placental alkaline phosphatase (hPAP) transgenic cells. We studied the effects of darbepoetin alfa treatment (EPO, 40 microg/kg, every 3 weeks, starting 3 weeks after MI) on longitudinal changes in left ventricular (LV) function, circulating EPC, myocardial histology, and expression of vascular endothelial growth factor (VEGF) determined 9 weeks after MI. EPO prevented LV-dilatation and improved cardiac function (all P < 0.05), which was associated with 42% increased capillary growth (P < 0.01). EPO-induced mobilization of EPC from the bone marrow (P < 0.01), which resulted in a three-fold increased homing of EPC into the cardiac microvasculature. The percentage of the endothelium that consisted of bone marrow derived cells was significantly increased (3.9 +/- 0.5 vs. 11.4 +/- 1%, P < 0.001) comprising 30% of the newly formed capillaries. In addition, EPO treatment resulted in a 4.5-fold increased myocardial expression of VEGF, which correlated strongly with neovascularization (r = 0.67; P < 0.001). VEGF was equally expressed by endothelial cells of myocardial and bone marrow origin. CONCLUSION: EPO-induced neovascularization in post-MI heart failure is mediated through a combination of EPC recruitment from the bone marrow and increased myocardial expression of VEGF.

A single bolus of a long-acting erythropoietin analogue darbepoetin alfa in patients with acute myocardial infarction: a randomized feasibility and safety study.

AIMS: Besides stimulating hematopoiesis, erythropoietin (EPO) protects against experimental ischemic injury in the heart. The present study evaluated the safety and tolerability of EPO treatment in non-anemic patients with acute myocardial infarction (MI). METHODS AND RESULTS: In this single-center, investigator-initiated, prospective study, patients with a first acute MI were randomized to one bolus of 300 microg darbepoetin alfa or no additional medication before primary coronary intervention. Twenty-two patients (mean age 59 +/- 2 years) were included. In the darbepoetin group, serum EPO-levels increased to 130-270 times that of controls, within the first 24 h. After darbepoetin administration, only small and non-significant changes in hematocrit levels were observed, while endothelial progenitor cells (EPCs, CD34+/CD45-) were increased at 72 h (2.8 vs. 1.0 cells/microl in control group, p < 0.01). No adverse events were recorded during the 30-day follow-up. After 4 months, left ventricular ejection fraction was similar in the two groups (52 +/- 3% in darbepoetin vs. 48 +/- 5% in control group, p = NS). CONCLUSIONS: Intravenous single high-dose darbepoetin alfa in acute MI is both safe and well tolerated. Darbepoetin treatment after MI stimulates EPCs mobilization. The results of this first pilot study support a larger scale clinical trial to establish efficacy of EPO administration in patients after acute MI.

Erythropoietin induces neovascularization and improves cardiac function in rats with heart failure after myocardial infarction.

OBJECTIVES: We assessed the effects of erythropoietin (EPO) treatment in a rat model of post-myocardial infarction (MI) heart failure. BACKGROUND: Erythropoietin, traditionally known as a hematopoietic hormone, has been linked to neovascularization. Whereas administration of EPO acutely after MI reduces infarct size and improves cardiac function, its role in the failing heart is unknown. METHODS: Rats underwent coronary ligation or sham surgery. Rats with MI were randomly assigned to: untreated (MI), a single bolus of EPO immediately after MI induction (MI-EPO-early), EPO treatment immediately after MI and once every three weeks (MI-EPO-early+late), and EPO treatment starting three weeks after induction of MI, once every three weeks (MI-EPO-late). After nine weeks, hemodynamics, infarct size, myosin heavy chain (MHC) isoforms, myocyte hypertrophy, and capillary density were measured. RESULTS: Erythropoietin treatment started immediately after MI (MI-EPO-early and MI-EPO-early+late) resulted in a 23% to 30% reduction in infarct size (p < 0.01) and, accordingly, hemodynamic improvement. Erythropoietin treatment, started three weeks after MI (MI-EPO-late), did not affect infarct size, but resulted in an improved cardiac performance, reflected by a 34% reduction in left ventricular end-diastolic pressure (p < 0.01), and 46% decrease in atrial natriuretic peptide levels (p < 0.05). The improved cardiac function was accompanied by an increased capillary density (p < 0.01), an increased capillary-to-myocyte ratio (p < 0.05), and a partial reversal of beta-MHC (p < 0.05) in all treated groups. CONCLUSIONS: In addition to its effect on infarct size reduction, EPO treatment improves cardiac function in a rat model of post-MI heart failure. This observation may be explained by neovascularization, associated with an increased alpha-MHC expression.

Prognostic value of plasma erythropoietin on mortality in patients with chronic heart failure.

OBJECTIVES: This study aimed to investigate the prognostic importance of plasma erythropoietin (EPO) levels in chronic heart failure (CHF) patients. BACKGROUND: Anemia is common and is associated with an impaired survival in patients with CHF. Erythropoietin is a hematopoietic growth factor, upregulated in anemic conditions. Little is known about the pathophysiology of anemia in CHF and the prognostic importance of plasma EPO levels in CHF patients. METHODS: In 74 patients with CHF (age, 61 +/- 2 years; left ventricular ejection fraction, 0.31 +/- 0.01; peak oxygen consumption, 19.1 +/- 0.6 [mean +/- SEM]) and in 15 control patients, hemoglobin levels and plasma concentrations of EPO and brain natriuretic peptide were measured. RESULTS: During a mean follow-up of 3.0 years (range, 2.3 to 5.3 years), 22 patients (30%) died. Anemia was present in 24% of the patients. Multivariate analysis showed that plasma EPO (p = 0.026) and hemoglobin levels (p = 0.005) were independent predictors of survival in this CHF population. We observed only a mild inverse correlation between the logarithm of EPO and hemoglobin levels (r2 = 0.08, p = 0.02) in CHF patients, whereas the control group showed a clear significant inverse correlation (r2 = 0.44, p = 0.007). CONCLUSIONS: Elevated plasma EPO levels are associated with an impaired prognosis independent of hemoglobin levels and other established markers of CHF severity. Furthermore, in the CHF patients, EPO levels poorly correlate with the hemoglobin levels, in contrast with the control group.