Thin-cap fibroatheroma predicts clinical events in diabetic patients with normal fractional flow reserve: the COMBINE OCT-FFR trial

AIMS

The aim of this study was to understand the impact of optical coherence tomography (OCT)-detected thin-cap fibroatheroma (TCFA) on clinical outcomes of diabetes mellitus (DM) patients with fractional flow reserve (FFR)-negative lesions.

METHODS AND RESULTS

COMBINE OCT-FFR study was a prospective, double-blind, international, natural history study. After FFR assessment, and revascularization of FFR-positive lesions, patients with ≥1 FFR-negative lesions (target lesions) were classified in two groups based on the presence or absence of ≥1 TCFA lesion. The primary endpoint compared FFR-negative TCFA-positive patients with FFR-negative TCFA-negative patients for a composite of cardiac mortality, target vessel myocardial infarction, clinically driven target lesion revascularization or unstable angina requiring hospitalization at 18 months. Among 550 patients enrolled, 390 (81%) patients had ≥1 FFR-negative lesions. Among FFR-negative patients, 98 (25%) were TCFA positive and 292 (75%) were TCFA negative. The incidence of the primary endpoint was 13.3% and 3.1% in TCFA-positive vs. TCFA-negative groups, respectively (hazard ratio 4.65; 95% confidence interval, 1.99-10.89; P < 0.001). The Cox regression multivariable analysis identified TCFA as the strongest predictor of major adverse clinical events (MACE) (hazard ratio 5.12; 95% confidence interval 2.12-12.34; P < 0.001).

CONCLUSIONS

Among DM patients with ≥1 FFR-negative lesions, TCFA-positive patients represented 25% of this population and were associated with a five-fold higher rate of MACE despite the absence of ischaemia. This discrepancy between the impact of vulnerable plaque and ischaemia on future adverse events may represent a paradigm shift for coronary artery disease risk stratification in DM patients.

Lack of statin therapy is associated with plaque instability in non-culprit non-ischemic lesions of diabetic patients – data from the COMBINE OCT-FFR study

Background

Effect of statin therapy on coronary plaque stabilisation and reducing adverse cardiovascular events is well known both in primary and secondary prevention. Nevertheless, there is a paucity of data presenting the impact of statins on plaque morphology as assessed by optical coherence tomography (OCT).

Purpose

The goal of this analysis was to evaluate the plaque morphology using OCT within non-culprit, non-ischaemic coronary lesions in diabetes mellitus (DM) patients with or without statin pre-treatment.

Methods

All patients of the COMBINE (FFR-OCT) trial underwent fractional flow reserve (FFR) measurement followed by OCT in FFR negative lesions. OCT recorded the presence of thin-cap fibroatheroma (TCFA), plaque rupture (PR), plaque erosion (PE) and calcified nodule (CN).

Results

From the 391 patients, 82 (21%) had no statin at baseline. OCT was performed in 463 lesions of which 96 lesions assessed in statin naive and 367 lesions in statin treated group. The median angiographic diameter stenosis was 50% and the median FFR value was 0.88 in both groups (p=0.953 and p=0.448, respectively). Myocardial infarction (MI) at presentation was 16.6% and did not differ between groups (p=0.380). Patients without statin pre-treatment were characterized by lower rate of known hypercholesterolemia (47.6% vs. 63.0%; p=0.011), male gender (52.4% vs. 65.7%; p=0.027), active smokers (8.5% vs. 22.3%; p=0.004) and previous MI (22.0% vs. 35.3%; p=0.022) as compared to patients with statin pre-treatment, respectively. The results of the qualitative OCT findings see in Table 1.

Conclusions

Non-ischemic lesions of DM patients without statin pre-treatment showed more vulnerable and instable plaque features like wider lipid arc, thinner fibrotic cap and a higher prevalence of lipid-rich plaque, TCFA and PR suggesting a stabilizing effect of statins on non-ischemic atherosclerotic lesions.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): The trial is founded from the Department of Cardiology Zwolle Heart-centrum with support from a non-restricted grant from St Jude Medical (now Abbott)

Everolimus-eluting bioresorbable scaffolds and metallic stents in diabetic patients: a patient-level pooled analysis of the prospective ABSORB DM Benelux Study, TWENTE and DUTCH PEERS

Background

Several studies compared everolimus-eluting bioresorbable scaffolds (EE-BRS) with everolimus-eluting stents (EES), but only few assessed these devices in patients with diabetes mellitus.

Aim

To evaluate the safety and efficacy outcomes of all-comer patients with diabetes mellitus up to 2 years after treatment with EE-BRS or EES.

Methods

We performed a post hoc pooled analysis of patient-level data in diabetic patients who were treated with EE-BRS or EES in 3 prospective clinical trials: The ABSORB DM Benelux Study (NTR5447), TWENTE (NTR1256/NCT01066650) and DUTCH PEERS (NTR2413/NCT01331707). Primary endpoint of the analysis was target lesion failure (TLF): a composite of cardiac death, target vessel myocardial infarction or clinically driven target lesion revascularization. Secondary endpoints included major adverse cardiac events (MACE): a composite of all-cause death, any myocardial infarction or clinically driven target vessel revascularization, as well as definite or probable device thrombosis (ST).

Results

A total of 499 diabetic patients were assessed, of whom 150 received EE-BRS and 249 received EES. Total available follow-up was 222.6 patient years (PY) in the EE-BRS and 464.9 PY in the EES group. The adverse events rates were similar in both treatment groups for TLF (7.2 vs. 5.2 events per 100 PY, p = 0.39; adjusted hazard ratio (HR) = 1.48 (95% confidence interval (CI): 0.77–2.87), p = 0.24), MACE (9.1 vs. 8.3 per 100 PY, p = 0.83; adjusted HR = 1.23 (95% CI: 0.70–2.17), p = 0.47), and ST (0.9 vs. 0.6 per 100 PY, p > 0.99).

Conclusion

In this patient-level pooled analysis of patients with diabetes mellitus from 3 clinical trials, EE-BRS showed clinical outcomes that were quite similar to EES.

The role of D2 dopamine receptors in oxytocin induced place preference and anxiolytic effect

Neuropeptide oxytocin (OT) is involved in the regulation of social and non-social behaviour. The central nucleus of amygdala (CeA), part of the limbic system, plays an important role in learning, memory, anxiety and reinforcing mechanisms. CeA has been shown to be rich in OT receptors in rodents. Our previous findings indicated that OT in the rat CeA has a dose dependent rewarding and anxiolytic effect. The aim of our present study was to examine in the CeA the possible interaction of OT and D2 dopamine (DA) receptor antagonist Sulpiride on reinforcement in place preference test and on anxiety in elevated plus maze test. Wistar rats were microinjected bilaterally with 10 ng OT. In different group of animals 4 μg D2 DA receptor antagonist was applied. Other animals received D2 DA receptor antagonist 15 min before 10 ng OT treatment or vehicle solution into the CeA. Rats receiving 10 ng OT spent significantly longer time in the treatment quadrant during the test session in conditioned place preference test. Prior treatment with D2 DA receptor antagonist blocked the rewarding effects of OT. Antagonist in itself did not influence the time rats spent in the treatment quadrant. In elevated plus maze test, rats receiving 10 ng OT spent significantly longer time on the open arms. Prior treatment with D2 DA receptor antagonist blocked the effects of OT. Our results show that DA system plays a role in positive reinforcing and anxiolytic effects of OT because D2 DA receptor antagonist can block these actions.

P6413Aging increases the plaque vulnerability in non-ischemic non-culprit lesions of diabetic patients, data from COMBINE OCT-FFR study

Background

Little is known about age-related differences in baseline atherosclerotic plaque morphology and composition in patients with diabetes mellites (DM).

Purpose

For this purpose, we studied DM patients from the Combine trial.

Methods

COMBINE (OCT-FFR, NCT02989740) is a multi-center, prospective study focusing on the natural history of non-ischemic, non-culprit coronary lesions and evaluate whether certain OCT-assessed variables could predict future adverse events originating from these lesions in a DM population. OCT analysis identifies plaque composition, estimates calcium arc (o), lipid arc (o), and measures thickness of the fibrous cap covering the lipid core. Moreover, OCT records the presence of typical plaque vulnerability traits like thin fibrous cap atheroma (TCFA), plaque erosion (PE), plaque rupture (PR), calcification nodule (CN), heterogeneous tissues (a probably healed plaque rupture), and macrophages accumulation (bright spots). A dedicated software estimated the interpolated percentage area stenosis (AS, %) measuring the minimal lumen area (MLA) and reference vessel area. The present analysis reports the baseline morphology of these lesions respectively in young (<70 years) vs. old (≥70 years) DM patients.

Results

OCT imaging was performed in 300 patients (361 lesions) from the COMBINE study, of which 203 lesions assessed in young and 158 lesions in old DM patients. There were no significant differences in MLA (mm2) 2.40 (1.85–315 vs. 2.30 (1.80–3.00), p=0.92), lesions length (mm 24.11 (15.10–33.10) vs. 24.20 (15.10–35.10), p=0.78), AS% (%) 63 (1.85–3.15) vs. 64 (56–73), p=0.41; lipid arc (o), 182 (140–250) vs. 175 (128–240), p=0.35), fibrous cap thickness covering the lipid arc (μm), 117 (65–193) vs. 110 (64–168), p=0.45, in the prevalence of TCFA 37 (18%) vs. 33 (21%), p=0.53, PR 17 (18%) vs. 15 (10%), p=0.71, heterogenous tissue 39 (19%) vs. 31 (20%), p=0.92, and bright spots 98 (48%) vs. 69 (44%), p=0.38. The patients ≥70 years had a higher prevalence of calcified plaques 171 (84%) vs. 143 (90%), p=0.08 and wider calcium arc. These lesions included more PE 7 (3%) vs. 13 (8%), p=0.05, CN 73 (36%) vs. 75 (47%), p=0.03, and CN associated with overlying thrombus 11 (5%) vs. 20 (13%), p=0.02.

Conclusion

Non-ischemic, non-culprit lesions in elderly DM patients present the same prevalence of soft, vulnerable plaques as it is a younger cohort, however, they have a higher prevalence of calcified plaque including complex calcified plaques as eroded plaques and calcification nodules with overlying thrombus. Whether these complex calcified plaques are associated with a higher risk of adverse events remains questionable and could be further elucidated from longer follow-up data of the COMBINE trial.

The 1‑year safety and efficacy outcomes of Absorb bioresorbable vascular scaffolds for coronary artery disease treatment in diabetes mellitus patients: the ABSORB DM Benelux study

Background

Diabetes mellitus (DM) patients show higher rates of repeat revascularisation even in the era of modern drug-eluting stents (DES). The concept of bioresorbable scaffolds is becoming captivating, as it might allow for repeat interventions, prolonging the time span during which patients can be treated by percutaneous coronary intervention (PCI).

Aims

We intend to evaluate the short- and long-term safety and efficacy of Absorb bioresorbable vascular scaffolds (Absorb BVS) in the treatment of coronary artery disease (CAD) in DM patients for any indication.

Methods

The ABSORB DM Benelux is an international prospective study in DM patients who have undergone PCI with ≥1 Absorb BVS. Major adverse cardiac events (MACE) at 1 year was the primary endpoint, defined as a composite of all-cause death, any myocardial infarction (MI) and ischaemia-driven target vessel revascularisation (TVR). Secondary endpoints were target lesion failure (TLF) and definite or probable scaffold thrombosis (ScT).

Results

Between April 2015 and March 2017, 150 DM patients and 188 non-complex lesions were treated. Device implantation was successful in 100%. MACE occurred in 14 (9.5%) patients, with all-cause death occurring in 4 (2.7%), any MI in 6 (4.1%) and ischaemia-driven TVR in 7 (4.8%) respectively. TLF was reported in 11 (7.5%). Definite and probable ScT was observed in 2 (1.4%).

Conclusion

Absorb BVS for treatment of anatomically low-risk patients with DM show acceptable safety and efficacy outcomes at 1 year. If these promising results are confirmed after a longer follow-up period, new-generation bioresorbable scaffolds combined with refinement of implantation techniques might open new horizons for CAD treatment in DM patients.

Electronic supplementary material

The online version of this article (10.1007/s12471-019-1293-7) contains supplementary material, which is available to authorised users.

Everolimus-eluting bioresorbable scaffolds for treatment of coronary artery disease in patients with diabetes mellitus: the midterm follow-up of the prospective ABSORB DM Benelux study

Background

Percutaneous coronary intervention (PCI) in patients with diabetes mellitus (DM) remains challenging even with modern drug-eluting stents (DES) due to high rates of repeat revascularization. Everolimus-eluting bioresorbable scaffolds (EE-BRS) might allow for repeat intervention prolonging the time interval of percutaneous treatment options.

Methods

The ABSORB DM Benelux Study is a dedicated prospective, international study to evaluate the midterm safety and efficacy of EE-BRS in DM patients. All DM patients that received ≥ 1 EE-BRS for any indication were enrolled and prospectively followed. Study endpoints were major adverse cardiac events (MACE): a composite of all-cause death, any myocardial infarction (MI) and ischemic-driven target vessel revascularization (TVR); target lesion failure (TLF): a composite of cardiac death (CD), target vessel MI, and ischemic-driven target lesion revascularization (TLR), as well as definite or probable scaffold thrombosis (ScT).

Results

Between April 2015 till March 2017, 150 DM patients and 188 lesions were treated and followed up to 3 years. Device implantation success was 100%. MACE occurred in 15.2% (event rate of 8.8 per 100 PY). TLF was reported in 11.7% (7.0 events per 100 PY). CD, target vessel MI, ischemic-driven TLR occurred in 3.4%, 3.6% and 5.5% respectively, while ScT was observed in 1.4%. There were no occurrences of late or very late ScT.

Conclusion

EE-BRS treatment in DM patients shows comparable midterm safety and efficacy outcomes when historically compared with modern DES. New-generation EE-BRS might offer an attractive alternative to metallic DES in treatment of fast progressing atherosclerosis population as in DM patients.

Trial registration NTR5447. Registered 05 October 2015, retrospectively registered

Factors associated with deferred lesion failure following fractional flow reserve assessment in patients with diabetes mellitus

OBJECTIVE

To explore the predictors of deferred lesion failure (DLF) in patients with diabetes mellitus (DM) and lesions with a fractional flow reserve (FFR) >0.80 and to examine whether a predictive relationship between negative FFR values (>0.80-1.00) and DLF exists.

BACKGROUND

DM is associated with rapidly progressive atherosclerosis and predictors of DLF in FFR negative lesions in this high-risk group are unknown.

METHODS

All DM patients who underwent FFR-assessment between 1/01/2010 and 31/12/2013 were included, and followed until 1/7/2015. Patients carrying ≥1 FFR negative lesion(s) were assessed for DLF, and multivariate models used to identify independent factors associated with DLF.

RESULTS

A total of 205 patients with 252 FFR >0.80 lesions were identified. At a mean follow-up of 3.1 ± 1.4 years, DLF occurred in 29/205 (14.1%) patients, 31/252 (12.3%) lesions. Using marginal Cox regression multivariate analysis, insulin requiring DM [HR 2.24 (95%CI; 1.01-4.95), P = 0.046] and prior revascularization [HR 2.70 (95%CI 1.21-6.01), P = 0.015] were identified as being associated with a higher incidence of DLF. Absolute FFR values in FFR negative lesions in DM patients are not predictive of DLF (receiver operating characteristics curve analysis: area under the curve: 0.57 ± 0.06, 95%CI 0.46-0.69).

CONCLUSIONS

In DM patients with FFR negative lesions, insulin requiring DM and prior revascularization are predictors for DLF. In contrast to non-DM patients, no predictive relationship between absolute negative FFR values (ranging >0.80-1.00) and the risk of DLF exists in DM patients. © 2017 Wiley Periodicals, Inc.

Transradial and transulnar access for iliac artery interventions using sheathless guiding systems: A feasibility study

PURPOSE

Our aim was to evaluate the acute success and complication rates of the transradial and transulnar access for iliac artery stenting using sheathless guiding systems.

METHODS

Clinical and angiographic data from 156 consecutive patients with symptomatic iliac artery stenosis who were treated with transradial or transulnar access were evaluated. All patients underwent Duplex ultrasound before and after the intervention. The primary endpoints were the procedural success rate, major adverse events, and access site complication rates. The secondary endpoints were the angiographic result of the iliac artery intervention, fluoroscopy time, X-ray dose, procedure length, crossover rate to another puncture site and hospitalization duration. The impact of the learning curve was also investigated, along with right or left radial access.

RESULTS

The indication for the intervention was intermittent claudication in 109 patients (69.9%), critical limb ischemia in 44 (28.2%) subjects and acute limb ischemia in three individuals (1.9%). Technical success was achieved in 155 patients (99.4%), with a crossover rate of 3.8%. Radial and ulnar artery access was used in 151 (96.8%) and 7 (4.5%) patients, respectively. The Ankle-brachial index increased from 0.69 [0.65-0.72] to 0.91 [0.88-0.95] as a result of the procedures (P < 0.001). The cumulative incidence of major adverse events was 3.8% at the 2-month follow-up (0% in patients with intermittent claudication and 13.8% in patients with critical limb ischemia). Radial artery access site complications were encountered in eight patients (5.1%). We documented decreased X-ray doses (1742.0 [783.9-2701] vs. 1435 [991.1-1879] vs. 692.8 [275.3-1110] Gy cm-2 P < 0.05) over time; however, the fluoroscopy time, procedure time, and contrast consumption were not significantly different. Left hand access was not associated with significantly better results than right radial artery access.

CONCLUSIONS

Iliac artery stenting can be safely and effectively performed using radial or ulnar artery access and sheathless guiding catheters, with acceptable complication rates and high levels of technical success. The physician learning curve plays an important role in decreasing the X-ray dose. © 2016 The Authors. Catheterization and Cardiovascular Interventions Published by Wiley Periodicals, Inc.

Efficacy of drug-eluting balloon in patients with bare-metal or drug-eluting stent restenosis

INTRODUCTION

In spite of improving results, the treatment of in-stent restenosis (ISR) of bare-metal stents (BMS), and particularly drug-eluting stents (DES), is a challenging clinical problem. There are promising but limited follow-up data concerning drug-eluting balloons in the treatment of BMS and DES restenosis. The goal of this real-world registry was to assess the long-term safety and efficacy of drug-eluting balloons in the treatment of BMS and DES restenosis.

METHODS

In this prospective registry, 82 patients with BMS or DES restenosis treated with paclitaxel-eluting balloons were enrolled. The primary endpoint was ischemia-driven target lesion revascularization (TLR); a secondary endpoint was the rate of major adverse cardiac events (MACE) at 28 months.

RESULTS

Thirty-five patients (42.7%) had DES ISR and 16 patients (19.5%) presented with an acute coronary syndrome. The success rate of drug-eluting balloon inflation was 97.6%. The median (interquartile range) duration of follow up was 28.0 (25.0-30.3) months. The rate of TLR was 24.5%, and was not significantly higher in the DES-ISR group than in the BMS-ISR group: 29.0% vs. 21.1%, respectively (p=0.687). There were two cases of definite stent thrombosis in the BMS-ISR group and one probable subacute stent thrombosis in the DES-ISR group. The overall MACE rate was 37.0% and did not differ between the DES-ISR and BMS-ISR group (40.8% vs. 34.7%, respectively; p=0.994).

CONCLUSIONS

This real-world registry provided less favorable long-term results for drug-eluting balloons in the treatment of BMS restenosis and in DES restenosis, compared to the promising mid-term results of previous studies. The TLR rate was slightly but not significantly higher after DES restenosis compared to BMS restenosis treatment.

Successful surgical restoration of a giant immature left ventricular aneurysm with computer assisted ventricle engineering

Background: Although circular ventricle resection techniques are the gold standard of left ventricle restoration, these techniques can lead to suboptimal results. Postoperative systolic resection line can be inadequate, as it must be planned on a heart stopped in diastole. The impaired geometry and contractility may lead to increased short- and long-term mortality. Moreover, postoperative low cardiac output due to insufficient left ventricular volume results in a potentially unstable condition, and cannot be corrected. Our aim was to find a preoperative method to minimize risk and maximize outcome with left ventricle restoration. Methods: We have created a novel method combining surgery with modern imaging techniques to construct a preoperative 3D systolic heart model. The model was utilized to determine resection could be intraoperatively used to create the new left ventricle. Results: The computer assisted ventricle engineering technique is described step by step through a successful aneurysmectomy of a 61-year-old female patient with a complicated giant left ventricle aneurysm. Conclusions: Using this model we are able to find the optimal resection line providing excellent postoperative result, thus minimizing the risk of low cardiac output syndrome. This is the first report of our new combined approach to left ventricle restoration.

Significance of off-hours in centralized primary percutaneous coronary intervention network

AIM

To analyze the efficacy of a regionally organized primary percutaneous coronary intervention (PCI) network at the Heart Center, Semmelweis University Budapest, part of the "Budapest model," and the factors that influence it.

METHODS

In order to investigate the differences between regular and off-hours patient care in a 24-hour myocardial infarction primary care system, we included 1890 consecutive, unselected patients with ST-segment elevation myocardial infarction and followed them until at least one year. The follow-up was complete for all participants.

RESULTS

The difference between regular hours and off-hours mortality was not significant either after 30 days (8.6% vs 8.8%, respectively) or after 1 year (15.3% vs 14.7%, respectively). The rate of patients with re-infarction, frequency of re-intervention, and major adverse cardiac events, including death, re-infarction, re-intervention, and coronary artery bypass graft surgery, were similar in both patient groups. The time delay between the onset of chest pain and arrival to the clinic was 5.9+/-5.8 hours (mean+/- standard deviation) during regular hours and 5.2+/-4.6 hours during off-hours (P=0.235). Direct transport caused significant decrease in the 30-day and 1-year mortality independent of duty time (7.2% vs 9.9%, P=0.027; 12.6% vs 16.7%, P=0.028; respectively).

CONCLUSION

Centralized primary PCI network of the "Budapest model" achieved the same level of patient care during both off-hours and regular hours.

Cross-cultural adaptation of the disabilities of the arm, shoulder, and hand (DASH) questionnaire into Hungarian and investigation of its validity in patients with systemic sclerosis

OBJECTIVE

To adapt and validate the Hungarian version of the DASH and the shorter QuickDASH Outcome Measures and to establish their validity in patients with systemic sclerosis (SSc).

METHODS

The Hungarian adaptation of the questionnaires was performed using forward/backward translations, expert and lay reviews. 128 patients completed the DASH, the Health Assessment Questionnaire (HAQ-DI), the Modified HAQ-DI for patients with SSc (SSc-HAQ), and the Short Form Health Survey (SF-36) questionnaire. 76 patients participated in a 12-month follow-up examination. Sensitivity to change was estimated using the standardized response mean (SRM).

RESULTS

Cronbach alpha in the DASH sections were between 0.94-0.97. The intraclass correlation coefficient for the test-retest reliability of DASH was 0.89. DASH scores showed a correlation with both SSc-HAQ and the physical dimensions of the SF-36 (Spearman's rho: 0.89, -0.77 and -0.42, respectively). The SRM of DASH was 0.64 among the scleroderma patients with worsening HAQ-DI status.

CONCLUSIONS

The Hungarian version of the DASH and QuickDASH demonstrated equivalent reproducibility, internal consistency and validity to the originals. The strong correlations of the DASH and QuickDASH with the HAQ-DI, and with the physical dimensions of the SF-36 show that the disability of the patient with SSc is predominantly caused by the functional impairment of the upper limb. Because both questionnaires were valuable tools for measuring upper extremity function and joint damage in SSc patients, we recommend the shorter and simpler QuickDASH for everyday clinical use.

Alterations of conditioned taste aversion after microiontophoretically applied neurotoxins in the medial prefrontal cortex of the rat

The prefrontal cortex (PFC) has been reported to be essential in neural control of feeding. In the present study, we aimed to provide a complex characterization of behavioral consequences of PFC microlesions in CFY rats. Kainic acid (KA) was microiontophoretically applied into the mediodorsal division of PFC to damage intrinsic neurons, whereas in another group of rats, 6-hydroxydopamine (6-OHDA) was microiontophoretized into the same region to destroy catecholaminergic (CA) projection fiber terminals. Body weights, food and fluid intake of both lesioned and (sham-operated or intact) control animals were daily measured. Effects of intracellular dehydration and water deprivation were also studied. Open field activity, stereotyped behaviors, and orientation towards visual and somesthetic stimuli were pre- and postoperatively tested. To examine hypothesized consequences of mPFC microlesions on central taste information processing, the acquisition and retention of saccharine conditioned taste aversion (CTA) were studied. No major changes were recorded in body weights, food and water consumption. Dehydration or deprivation similarly increased water intake in all animals. Scores of open field activity and stereotyped behaviors in the 6-OHDA group were significantly higher than those of the other groups. As the main findings of the present studies, both KA and 6-OHDA lesioned rats displayed significant deficits in CTA acquisition and retention tests. These results suggest that the medial PFC has a substantial role in both the formation and the retrieval of CTA. Furthermore, the present findings also indicate the general significance of prefrontal CA mechanisms in the organization of goal-directed, adaptive behaviors.