Clinical outcomes of fractional flow reserve by computed tomographic angiography-guided diagnostic strategies vs. usual care in patients with suspected coronary artery disease: the prospective longitudinal trial of FFR(CT): outcome and resource impacts study.

AIMS: In symptomatic patients with suspected coronary artery disease (CAD), computed tomographic angiography (CTA) improves patient selection for invasive coronary angiography (ICA) compared with functional testing. The impact of measuring fractional flow reserve by CTA (FFRCT) is unknown. METHODS AND RESULTS: At 11 sites, 584 patients with new onset chest pain were prospectively assigned to receive either usual testing (n = 287) or CTA/FFR(CT) (n = 297). Test interpretation and care decisions were made by the clinical care team. The primary endpoint was the percentage of those with planned ICA in whom no significant obstructive CAD (no stenosis ≥50% by core laboratory quantitative analysis or invasive FFR < 0.80) was found at ICA within 90 days. Secondary endpoints including death, myocardial infarction, and unplanned revascularization were independently and blindly adjudicated. Subjects averaged 61 ± 11 years of age, 40% were female, and the mean pre-test probability of obstructive CAD was 49 ± 17%. Among those with intended ICA (FFR(CT)-guided = 193; usual care = 187), no obstructive CAD was found at ICA in 24 (12%) in the CTA/FFR(CT) arm and 137 (73%) in the usual care arm (risk difference 61%, 95% confidence interval 53-69, P< 0.0001), with similar mean cumulative radiation exposure (9.9 vs. 9.4 mSv, P = 0.20). Invasive coronary angiography was cancelled in 61% after receiving CTA/FFR(CT) results. Among those with intended non-invasive testing, the rates of finding no obstructive CAD at ICA were 13% (CTA/FFR(CT)) and 6% (usual care; P = 0.95). Clinical event rates within 90 days were low in usual care and CTA/FFR(CT) arms. CONCLUSIONS: Computed tomographic angiography/fractional flow reserve by CTA was a feasible and safe alternative to ICA and was associated with a significantly lower rate of invasive angiography showing no obstructive CAD.

Longitudinal analysis of the electroencephalogram and sleep phenotype in the R6/2 mouse model of Huntington's disease.

Deficits in sleep and circadian organization have been identified as common early features in patients with Huntington's disease that correlate with symptom severity and may be instrumental in disease progression. Studies in Huntington's disease gene carriers suggest that alterations in the electroencephalogram may reflect underlying neuronal dysfunction that is present in the premanifest stage. We conducted a longitudinal characterization of sleep/wake and electroencephalographic activity in the R6/2 mouse model of Huntington's disease to determine whether analogous electroencephalographic 'signatures' could be identified early in disease progression. R6/2 and wild-type mice were implanted for electroencephalographic recordings along with telemetry for the continuous recording of activity and body temperature. Diurnal patterns of activity and core body temperature were progressively disrupted in R6/2 mice, with a large reduction in the amplitude of these rhythms apparent by 13 weeks of age. The diurnal variation in sleep/wake states was gradually attenuated as sleep became more fragmented and total sleep time was reduced relative to wild-type mice. These genotypic differences were augmented at 17 weeks and evident across the entire 24-h period. Quantitative electroencephalogram analysis revealed anomalous increases in high beta and gamma activity (25-60 Hz) in all sleep/wake states in R6/2 mice, along with increases in theta activity during both non-rapid eye movement and rapid eye movement sleep and a reduction of delta power in non-rapid eye movement sleep. These dramatic alterations in quantitative electroencephalographic measures were apparent from our earliest recording (9 weeks), before any major differences in diurnal physiology or sleep/wake behaviour occurred. In addition, the homeostatic response to sleep deprivation was greatly attenuated with disease progression. These findings demonstrate the sensitivity of quantitative electroencephalographic analysis to identify early pathophysiological alterations in the R6/2 model of Huntington's disease and suggest longitudinal studies in other preclinical Huntington's disease models are needed to determine the generality of these observations as a potential adjunct in therapeutic development.

Premature ventricular complexes: Assessing burden density in a large national cohort to better define optimal ECG monitoring duration.

BACKGROUND: Premature ventricular contraction (PVC) burden is a risk factor for heart failure and cardiovascular death in patients with structural heart disease. Long-term electrocardiographic monitoring can have a significant impact on PVC burden evaluation by further defining PVC distribution patterns. OBJECTIVE: This study aimed to ascertain the optimal duration of electrocardiographic monitoring to characterize PVC burden and to understand clinical characteristics associated with frequent PVCs and nonsustained ventricular tachycardia in a large US cohort. METHODS: Commercial data (iRhythm's Zio patch) from June 2011 to April 2022 were analyzed. Inclusion criteria were age >18 years, PVC burden ≥5%, and wear period ≥13 days. PVC burden cutoffs were determined on the basis of AHA/ACC/HRS guidelines for very frequent PVCs (10,000-20,000 during 24 hours). Patients were assigned to categories by PVC densities: low, <10%; moderate, 10% to <20%; and high, ≥20%. Mean measured error was assessed at baseline and daily until the wear period's end for overall PVC burden and different PVC densities. RESULTS: Analysis of 106,705 patch monitors revealed a study population with mean age of 70.6 ± 14.6 years (33.6% female). PVC burden was higher in male patients and those >65 years of age. PVC burden mean error decreased from 2.9% at 24 hours to 1.3% at 7 days and 0.7% at 10 days. Number of ventricular tachycardia episodes per patient increased with increasing PVC burden (P < .0001). CONCLUSION: Extending ambulatory monitoring beyond 24 hours to 7 days or more improves accuracy of assessing PVC burden. Ventricular tachycardia frequency and duration vary by initial PVC density, highlighting the need for prolonged cardiac monitoring.

Comparison of data quality and monitoring completion rates between clinic and self-applied ECG patches.

BACKGROUND: Since the onset of the coronavirus disease 2019 (COVID-19) pandemic, direct-to-patient, self-applied ECG patch use has substantially increased. There are limited data comparing clinic with self-applied electrocardiogram (ECG) patches. OBJECTIVE: The purpose of this study was to compare rates of ECG patch return, percentages of time patches yielded analyzable data (analyzable time), and percentages of prescribed time ECG patches were worn between clinic and self-applied ECG patches before and during COVID-19. METHODS: A retrospective analysis of patients prescribed an ECG patch during "pre-COVID" (March 1, 2019, through March 1, 2020) and "COVID" (April 4, 2020, through April 1, 2021) years was performed. ECG patch return rates, mean percentages of analyzable time, and mean percentages of prescribed wear time were compared between clinic and self-applied groups. RESULTS: Among the 29,093 ECG patch prescriptions (19% COVID self-applied), the COVID self-applied group had a lower return rate (90.8%) than did both clinic-applied groups (COVID: 97.1%; pre-COVID: 98.1%; P < .001). Among the 28,048 ECG patches (17.5% self-applied) returned for analysis, the COVID self-applied group demonstrated a lower mean percentage of analyzable time (95.9% ± 8.2%) than did both clinic-applied groups (COVID: 96.6% ± 6.6%; pre-COVID 96.6% ± 7.4%; P < .001). There were no differences in the mean percentage of prescribed wear time between groups (pre-COVID clinic-applied: 96.7% ± 34.3%; COVID clinic-applied: 97.4% ± 39.8%; COVID self-applied: 98.1% ± 52.1%; P = .09). CONCLUSION: Self-applied ECG patches were returned at a lower rate and had a statistically lower percentage of analyzable time than clinic-applied patches. However, there were no differences between groups in mean percentages of prescribed wear time, and mean percentages of analyzable time were >95% in all groups.

Delayed environmental enrichment reverses sevoflurane-induced memory impairment in rats.

BACKGROUND: Anesthesia given to immature rodents causes cognitive decline, raising the possibility that the same might be true for millions of children undergoing surgical procedures under general anesthesia each year. We tested the hypothesis that anesthesia-induced cognitive decline in rats is treatable. We also tested if anesthesia-induced cognitive decline is aggravated by tissue injury. METHODS: Seven-day old rats underwent sevoflurane anesthesia (1 minimum alveolar concentration, 4 h) with or without tail clamping. At 4 weeks, rats were randomized to environmental enrichment or normal housing. At 8 weeks rats underwent neurocognitive testing, which consisted of fear conditioning, spatial reference memory, and water maze-based memory consolidation tests, and interrogated working memory, short-term memory, and early long-term memory. RESULTS: Sevoflurane-treated rats had a greater escape latency when the delay between memory acquisition and memory retrieval was increased from 1 min to 1 h, indicating that short-term memory was impaired. Delayed environmental enrichment reversed the effects of sevoflurane on short-term memory and generally improved many tested aspects of cognitive function, both in sevoflurane-treated and control animals. The performance of tail-clamped rats did not differ from those rats receiving anesthesia alone. CONCLUSION: Sevoflurane-induced cognitive decline in rats is treatable. Delayed environmental enrichment rescued the sevoflurane-induced impairment in short-term memory. Tissue injury did not worsen the anesthesia-induced memory impairment. These findings may have relevance to neonatal and pediatric anesthesia.

Patient Characteristics and Healthcare Resource Utilization Among Patients with COPD New to LAMA/LABA Fixed-Dose Combination Treatment in US-Based Real-World Practice.

Introduction: This retrospective, observational cohort study utilized an integrated dataset from an electronic health records system and a claims database to describe demographic and clinical characteristics, healthcare resource utilization (HCRU), and treatment patterns in COPD patients initiating long-acting muscarinic antagonist (LAMA)/long-acting ß2-agonist (LABA) fixed-dose combination (FDC) treatment in the USA. Methods: Patients were aged ≥40 years and had a COPD diagnosis (Practice Fusion system) and ≥1 prescription of LAMA/LABA FDC therapy, with an index date (first prescription) 1 May 2014-31 December 2017. For the HCRU analysis, patients had ≥2 claims from the Symphony Health database within 12 months before index. All analyses of outcomes relating to demographic and clinical characteristics, HCRU, and treatment patterns were descriptive. Results: Patients initiating LAMA/LABA FDCs (n=8224) had a mean age of 67.9 years, 52.8% were female, and mean BMI was 29.2 kg/m2. The most common comorbidities were cardiovascular disease (74.3%), hypertension (64.0%), and hyperlipidemia (45.6%). In the 12 months prior to index, 53.1% of patients had used inhaled therapy: 23.4% short-acting therapy only, 16.7% short-acting and maintenance therapy, and 13.1% maintenance therapy only. Amongst users of inhaled therapies, the pMDI was the most frequently used device (64.3%, n=2812/4370). Of 7050 patients included in the HCRU analysis, 79.8% had COPD-related costs; mean cost/patient was $4174. Mean COPD-related costs per patient for moderate and severe exacerbations were $910 and $23,208, respectively. Per-patient costs included $23,032 for inpatient visits, $2358 for emergency visits, $4432 for outpatient visits, and $1989 for pharmacy claims. Conclusion: This observational study is the first to describe the real-world demographic and clinical characteristics and HCRU of patients initiating LAMA/LABA FDC treatment in the USA. Patients were generally elderly and overweight, with comorbidities of CVD, hypertension, and hyperlipidemia. Inpatient visits were the largest contributor to COPD-related costs per patient in the year prior to initiation of LAMA/LABA FDCs.

Clinical And Economic Burden Of Eosinophilic COPD In A Large Retrospective US Cohort.

Purpose: We sought to describe clinical and economic outcomes for COPD patients by blood eosinophil (EOS) count. Methods: This retrospective cohort study of COPD patients used data from the Practice Fusion electronic medical records (EMR) database linked to Symphony Health Solutions transactional pharmacy, medical, outpatient, and inpatient claims data to evaluate COPD-related and all-cause health care resource utilization and cost in the 12-month period following the date of each patient's greatest recorded blood eosinophil count during the 27-month period from January 2014 to March 2016. A post-index moderate exacerbation was defined as an outpatient or emergency care visit for COPD and a prescription for oral corticosteroid and/or antibiotics within 10 days of the visit. Severe exacerbation was defined as an inpatient hospitalization with COPD as primary diagnosis. Results: Of 48,090 EMR patients, 39,939 (83.1%) had a charge in the claims data both pre- and post-index (mean age 67.2 years, 58.3% female), 17,397 (43.6%) had EOS ≥220 cells/µL. Moderate and severe exacerbations were more frequent for patients with EOS≥220 cells/µL compared with those with EOS <220 cells/µL (moderate: 6.8% vs 6.1%, p<0.05; severe: 3.1% vs 2.5%, p<0.001). After adjustment for baseline clinical characteristics, each 100-unit increase in EOS count was associated with a significant 2.24% increase in total all-cause costs and 4.54% increase in total COPD-related costs (p<0.001 for both). COPD-related costs were significantly greater for patients with an EOS count of ≥220 cells/µL compared with those with EOS <220 cells/µL (p<0.001). These costs appear to have been driven by a greater percentage of patients in the ≥220 cells/µL cohort with COPD-related resource use including hospitalization, office visits, ambulatory procedures and pharmacy prescriptions. Conclusion: COPD patients with EOS counts ≥220 cells/µL were more likely to have had moderate or severe exacerbations and greater cost of care than those with EOS <220 cells/µL.

An FFRCT diagnostic strategy versus usual care in patients with suspected coronary artery disease planned for invasive coronary angiography at German sites: one-year results of a subgroup analysis of the PLATFORM (Prospective Longitudinal Trial of FFRCT: Outcome and Resource Impacts) study.

AIM: Diagnostic evaluation practices for suspected coronary artery disease (CAD) may vary between countries. Our objective was to compare a CT-derived fractional flow reserve (FFRCT) diagnostic strategy with usual care in patients with planned invasive coronary angiography (ICA) enrolled in the PLATFORM (Prospective Longitudinal Trial of FFRCT: Outcome and Resource Impacts) study at German sites. METHODS: Patients were divided into two consecutive observational cohorts, receiving either usual care or CT angiography (CTA)/FFRCT. The primary endpoint was the percentage of patients planned for ICA, with no obstructive CAD on ICA within 90 days. Secondary endpoints included death, myocardial infarction, unstable angina, hospitalisation leading to unplanned revascularisation, cumulative radiation exposure, estimated medical costs and quality of life (QOL) at 1 year. RESULTS: 116 patients were included. The primary endpoint occurred in 4 of the 52 patients (7.7%) in the CTA/FFRCT group and in 55 of the 64 patients (85.9%) in the usual care group (risk difference 78.2%, 95% CI 67.1% to 89.4%, p<0.001). ICA was cancelled in 40 of the 52 patients (77%) who underwent CTA/FFRCT. Clinical event rates were low overall. The mean radiation exposure was lower in the FFRCT versus the usual care group (7.28 vs 9.80 mSv, p<0.001). Mean estimated medical costs were €4217 (CTA/FFRCT) versus €6894 (usual care), p<0.001. Improvement in QOL (EQ-5D score) was greater in the FFRCT (+0.09 units) versus the usual care cohort (+0.03 units), p=0.04. CONCLUSIONS: In patients with suspected CAD planned for ICA at German sites, initial CTA/FFRCT compared with usual care was associated with a markedly reduced rate of ICA showing no obstructive CAD, lower cumulative radiation exposure and estimated costs and greater improvement in QOL.

FFR Derived From Coronary CT Angiography in Nonculprit Lesions of Patients With Recent STEMI.

OBJECTIVES: This study sought to determine the diagnostic performance of noninvasive fractional flow reserve (FFR) derived from coronary computed tomography angiography (CTA) (FFRCT) for the diagnosis of lesion-specific ischemia in nonculprit vessels of patients with recent in ST-segment elevation myocardial infarction (STEMI). BACKGROUND: In patients with stable angina, FFRCT has high diagnostic performance in identification of ischemia-causing lesions. The potential value of FFRCT for assessment of multivessel disease in patients with recent STEMI has not been evaluated. METHODS: Coronary CTA with calculation of FFRCT and invasive coronary angiography with FFR were performed 1 month after STEMI in patients with multivessel disease. Coronary CTA and invasive coronary angiography stenosis >50% were considered obstructive. Lesion-specific ischemia was assumed if FFRCT was ≤0.80. FFR ≤0.80 was the reference standard. To evaluate the influence of vessel size, the total coronary vessel lumen volume relative to left ventricular mass (volume-to-mass ratio) was calculated and compared with that of patients with stable angina. RESULTS: The study evaluated 124 nonculprit vessels from 60 patients. Accuracy, sensitivity, and specificity of FFRCT were 72%, 83%, and 66% versus 64% (p = 0.033), 93% (p = 0.15), and 49% (p < 0.001) for CTA and 72% (p = 1.00), 76% (p = 0.46), and 70% (p = 0.54) for invasive coronary angiography. Following STEMI, median volume-to-mass ratio was lower than in patients with stable angina, 53 versus 65 mm3/g (p = 0.009). In patients with volume-to-mass ratio ≥65 mm3/g (upper tertile) accuracy, sensitivity, and specificity of FFRCT were all 83% versus 56% (p = 0.009), 75% (p = 0.61), and 44% (p = 0.003) in patients with <49 mm3/g (lower tertile). CONCLUSIONS: The diagnostic performance of FFRCT for staged detection of ischemia in STEMI patients with multivessel disease is moderate. STEMI patients have a smaller vessel volume than do patients with stable angina. The diagnostic performance of FFRCT is influenced by the volume-to-mass ratio. This study does not support routine use of FFRCT in the post-STEMI setting. (Assessment of Coronary Stenoses Using Coronary CT-Angiography and Noninvasive Fractional Flow Reserve; NCT01739075).

Effect of the ratio of coronary arterial lumen volume to left ventricle myocardial mass derived from coronary CT angiography on fractional flow reserve.

BACKGROUND: We hypothesize that in patients with suspected coronary artery disease (CAD), lower values of the ratio of total epicardial coronary arterial lumen volume to left ventricular myocardial mass (V/M) result in lower fractional flow reserve (FFR). METHODS: V/M was computed in 238 patients from the NXT trial who underwent coronary computed tomography angiography (CTA), quantitative coronary angiography (QCA) and FFR measurement in 438 vessels. Nitroglycerin was administered prior to CT, QCA and FFR acquisition. The V/M ratio was quantified on a patient-level from CT image data by segmenting the epicardial coronary arterial lumen volume (V) and the left ventricular myocardial mass (M). Calcified and noncalcified plaque volumes were quantified using semi-automated software. RESULTS: The median value of V/M (18.57 mm3/g) was used to define equal groups of low and high V/M patients. Patients with low V/M had greater diameter stenosis by QCA, more plaque and lower FFR (0.80 ± 0.12 vs. 0.87 ± 0.08; P < 0.0001) than those with high V/M. A total of 365 vessels in 202 patients had QCA stenosis ≤50% and measured FFR. In these patients, those with low V/M had higher percent diameter stenosis by QCA, greater total plaque volume and lower FFR (0.81 ± 0.12 vs. 0.88 ± 0.07; P < 0.0001) than those with high V/M. In multivariate logistic regression analysis, V/M was an independent predictor of FFR ≤0.80 (all p-values < 0.001). CONCLUSIONS: Patients with a low V/M ratio have lower FFR overall and in non-obstructive CAD, independent of plaque measures.

1-Year Outcomes of FFRCT-Guided Care in Patients With Suspected Coronary Disease: The PLATFORM Study.

BACKGROUND: Coronary computed tomographic angiography (CTA) plus estimation of fractional flow reserve using CTA (FFRCT) safely and effectively guides initial care over 90 days in patients with stable chest pain. Longer-term outcomes are unknown. OBJECTIVES: The study sought to determine the 1-year clinical, economic, and quality-of-life (QOL) outcomes of using FFRCT instead of usual care. METHODS: Consecutive patients with stable, new onset chest pain were managed by either usual testing (n = 287) or CTA (n = 297) with selective FFRCT (submitted in 201, analyzed in 177); 581 of 584 (99.5%) completed 1-year follow-up. Endpoints were adjudicated major adverse cardiac events (MACE) (death, myocardial infarction, unplanned revascularization), total medical costs, and QOL. RESULTS: Patients averaged 61 years of age with a mean 49% pre-test probability of coronary artery disease. At 1 year, MACE events were infrequent, with 2 in each arm of the planned invasive group and 1 in the planned noninvasive cohort (usual care strategy). In the planned invasive stratum, mean costs were 33% lower with CTA and selective FFRCT ($8,127 vs. $12,145 usual care; p < 0.0001); in the planned noninvasive stratum, mean costs did not differ when using an FFRCT cost weight of zero ($3,049 FFRCT vs. $2,579; p = 0.82), but were higher when using an FFRCT cost weight equal to CTA. QOL scores improved overall at 1 year (p < 0.001), with similar improvements in both groups, apart from the 5-item EuroQOL scale scores in the noninvasive stratum (mean change of 0.12 for FFRCT vs. 0.07 for usual care; p = 0.02). CONCLUSIONS: In patients with stable chest pain and planned invasive coronary angiography, care guided by CTA and selective FFRCT was associated with equivalent clinical outcomes and QOL, and lower costs, compared with usual care over 1-year follow-up. (The PLATFORM Study: Prospective LongitudinAl Trial of FFRct: Outcome and Resource IMpacts [PLATFORM]; NCT01943903).

Quality-of-Life and Economic Outcomes of Assessing Fractional Flow Reserve With Computed Tomography Angiography: PLATFORM.

BACKGROUND: Fractional flow reserve estimated using computed tomography (FFRCT) might improve evaluation of patients with chest pain. OBJECTIVES: The authors sought to determine the effect on cost and quality of life (QOL) of using FFRCT instead of usual care to evaluate stable patients with symptoms suspicious for coronary disease. METHODS: Symptomatic patients without known coronary disease were enrolled into 2 strata based on whether invasive or noninvasive diagnostic testing was planned. In each stratum, consecutive observational cohorts were evaluated with either usual care or FFRCT. The number of diagnostic tests, invasive procedures, hospitalizations, and medications during 90-day follow-up were multiplied by U.S. cost weights and summed to derive total medical costs. Changes in QOL from baseline to 90 days were assessed using the Seattle Angina Questionnaire, the EuroQOL, and a visual analog scale. RESULTS: In the 584 patients, 74% had atypical angina, and the pre-test probability of coronary disease was 49%. In the planned invasive stratum, mean costs were 32% lower among the FFRCT patients than among the usual care patients ($7,343 vs. $10,734 p < 0.0001). In the noninvasive stratum, mean costs were not significantly different between the FFRCT patients and the usual care patients ($2,679 vs. $2,137; p = 0.26). In a sensitivity analysis, when the cost weight of FFRCT was set to 7 times that of computed tomography angiography, the FFRCT group still had lower costs than the usual care group in the invasive testing stratum ($8,619 vs. $ 10,734; p < 0.0001), whereas in the noninvasive testing stratum, when the cost weight of FFRCT was set to one-half that of computed tomography angiography, the FFRCT group had higher costs than the usual care group ($2,766 vs. $2,137; p = 0.02). Each QOL score improved in the overall study population (p < 0.0001). In the noninvasive stratum, QOL scores improved more in FFRCT patients than in usual care patients: Seattle Angina Questionnaire 19.5 versus 11.4, p = 0.003; EuroQOL 0.08 versus 0.03, p = 0.002; and visual analog scale 4.1 versus 2.3, p = 0.82. In the invasive cohort, the improvements in QOL were similar in the FFRCT and usual care patients. CONCLUSIONS: An evaluation strategy based on FFRCT was associated with less resource use and lower costs within 90 days than evaluation with invasive coronary angiography. Evaluation with FFRCT was associated with greater improvement in quality of life than evaluation with usual noninvasive testing. (Prospective Longitudinal Trial of FFRCT: Outcomes and Resource Impacts [PLATFORM]; NCT01943903).

The hypocretin/orexin antagonist almorexant promotes sleep without impairment of performance in rats.

The hypocretin receptor (HcrtR) antagonist almorexant (ALM) has potent hypnotic actions but little is known about neurocognitive performance in the presence of ALM. HcrtR antagonists are hypothesized to induce sleep by disfacilitation of wake-promoting systems whereas GABAA receptor modulators such as zolpidem (ZOL) induce sleep through general inhibition of neural activity. To test the hypothesis that less functional impairment results from HcrtR antagonist-induced sleep, we evaluated the performance of rats in the Morris Water Maze in the presence of ALM vs. ZOL. Performance in spatial reference memory (SRM) and spatial working memory (SWM) tasks were assessed during the dark period after equipotent sleep-promoting doses (100 mg/kg, po) following undisturbed and sleep deprivation (SD) conditions. ALM-treated rats were indistinguishable from vehicle (VEH)-treated rats for all SRM performance measures (distance traveled, latency to enter, time within, and number of entries into, the target quadrant) after both the undisturbed and 6 h SD conditions. In contrast, rats administered ZOL showed impairments in all parameters measured compared to VEH or ALM in the undisturbed conditions. Following SD, ZOL-treated rats also showed impairments in all measures. ALM-treated rats were similar to VEH-treated rats for all SWM measures (velocity, time to locate the platform and success rate at finding the platform within 60 s) after both the undisturbed and SD conditions. In contrast, ZOL-treated rats showed impairments in velocity and in the time to locate the platform. Importantly, ZOL rats only completed the task 23-50% of the time while ALM and VEH rats completed the task 79-100% of the time. Thus, following equipotent sleep-promoting doses, ZOL impaired rats in both memory tasks while ALM rats performed at levels comparable to VEH rats. These results are consistent with the hypothesis that less impairment results from HcrtR antagonism than from GABAA-induced inhibition.