P3584Optimal medical therapy improves survival in patients with ischaemic cardiomyopathy: an analysis of the STICH trial

Background

Prior studies have demonstrated underuse of optimal medical therapy (OMT) in patients with coronary artery disease (CAD) after revascularization. However, there are limited studies assessing compliance with OMT on long-term survival in patients with CAD and no studies evaluating the impact of OMT in patients with severe CAD and reduced left ventricular (LV) function. The Surgical Treatment for Ischaemic Heart Failure (STICH) Trial was a randomized clinical trial that compared coronary-artery bypass grafting (CABG) with medical therapy versus medical therapy alone in the treatment of ischemic cardiomyopathy.

Purpose

This study sought to determine compliance with OMT over time and the impact of OMT compliance on survival in patients with or without revascularization.

Methods

STICH was a multicenter, randomized clinical trial of patients with an LV ejection fraction of 35% or less and CAD amenable to CABG who were randomized to CABG plus medical therapy (N=610) or medical therapy alone (N=602). A medication history was obtained at hospital discharge or 30 days after enrollment, 1 year, 5 years, and 10 years. OMT was defined as the combination of at least 1 antiplatelet drug, a statin, a beta-blocker, and an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker. The primary outcome was all-cause mortality. Comparison of mortality between the OMT and non-OMT groups was performed using multivariate Cox regression modeling with OMT as a time-dependent covariate.

Results

Of the 1212 patients randomized, at a median follow-up of 9.8 years, all-cause mortality was 58.9% in the CABG group and 66.1% in the medical therapy group. In the CABG arm, 63.6% of patients were on OMT throughout the study period compared to 66.5% of patients in the medical therapy arm (p=0.3). Those on OMT were younger (59.6 vs. 61.4 years, p<0.001); were more often in NYHA class I-II (67.4% vs. 56%, p<0.001); and lower rates of atrial fibrillation (9.4% vs. 18.1%, p<0.001), current smoking (18.6% vs. 24.5%, p=0.015), and depression (4.8% vs. 8.8%, p=0.005). Those on OMT had higher rates of hyperlipidemia (63.8% vs. 54.4%, p=0.001) and prior myocardial infarction (79.4% vs. 73.1%, p=0.01). There was no difference in sex, diabetes, and hypertension between those on OMT and non-OMT. In multivariate survival analysis, OMT was associated with a significant reduction in mortality (adjusted hazard ratio, 0.69; 95% confidence interval, 0.58–0.81; p<0.001). The treatment effect with OMT (31% relative reduction in mortality over 10 years) was numerically greater than the treatment effect of CABG (24% relative reduction in mortality with CABG versus medical therapy alone).

Conclusions

OMT improves long-term survival in patients with ischaemic cardiomyopathy regardless of revascularization status. Strategies to improve OMT use and adherence in this population is needed to maximize survival.

Evolutionary signatures amongst disease genes permit novel methods for gene prioritization and construction of informative gene-based networks

Genes involved in the same function tend to have similar evolutionary histories, in that their rates of evolution covary over time. This coevolutionary signature, termed Evolutionary Rate Covariation (ERC), is calculated using only gene sequences from a set of closely related species and has demonstrated potential as a computational tool for inferring functional relationships between genes. To further define applications of ERC, we first established that roughly 55% of genetic diseases posses an ERC signature between their contributing genes. At a false discovery rate of 5% we report 40 such diseases including cancers, developmental disorders and mitochondrial diseases. Given these coevolutionary signatures between disease genes, we then assessed ERC's ability to prioritize known disease genes out of a list of unrelated candidates. We found that in the presence of an ERC signature, the true disease gene is effectively prioritized to the top 6% of candidates on average. We then apply this strategy to a melanoma-associated region on chromosome 1 and identify MCL1 as a potential causative gene. Furthermore, to gain global insight into disease mechanisms, we used ERC to predict molecular connections between 310 nominally distinct diseases. The resulting “disease map” network associates several diseases with related pathogenic mechanisms and unveils many novel relationships between clinically distinct diseases, such as between Hirschsprung's disease and melanoma. Taken together, these results demonstrate the utility of molecular evolution as a gene discovery platform and show that evolutionary signatures can be used to build informative gene-based networks.

Molecular evolution has informed our understanding of gene function; however, classical methods have largely been static in their implementation, focusing on single genes. Here, we present and prove the utility of a dynamic, network-based understanding of molecular evolution to infer relationships between genes associated with human diseases. We have shown previously that groups of genes within functional niches tend to share similar evolutionary histories. Exploiting the availability of whole genomes from multiple species, these histories can be numerically scored and dynamically compared to one another using a sequence-based signature termed Evolutionary Rate Covariation (ERC). To explore potential applications, we characterized ERC amongst disease genes and found that many diseases contain significant ERC signatures between their contributing genes. We show that ERC can also prioritize “true” disease genes amongst unrelated gene candidates. Lastly, these signatures can serve as a foundation for creating instructive gene-based networks, unveiling novel relationships between diseases thought to be clinically distinct. Our hope is that this study will add to the increasing evidence that advancing our understanding of molecular evolution can be a crucial asset in large-scale gene discovery pursuits (Link to our webserver that provides intuitive ERC analysis tools: http://csb.pitt.edu/erc_analysis/).

Differential permethrin susceptibility of head lice sampled in the United States and Borneo

BACKGROUND

Pediculiasis is treated aggressively in the United States, mainly with permethrin- and pyrethrin-containing pediculicides. Increasingly frequent anecdotal reports of treatment failure suggest the emergence of insecticidal resistance by these lice.

OBJECTIVE

To confirm or refute the susceptibility of head lice sampled in the United States to permethrin.

DESIGN

Survey. Head lice were removed from children residing where pediculicides are readily available and where such products are essentially unknown. Their survival was compared following exposure to residues of graded doses of permethrin in an in vitro bioassay.

SETTING

School children from Massachusetts, Idaho, and Sabah (Malaysian Borneo).

SUBJECTS

In the United States, 75 children aged 5 to 8 years. In Sabah, 59 boys aged 6 to 13 years. Virtually all sampled US children had previously been treated with pediculicides containing pyrethrins or permethrin; none of the Sabahan children were so exposed.

MAIN OUTCOME MEASURE

Survival of head lice exposed to permethrin.

RESULTS

Permethrin did not affect head lice sampled from chronically infested US children who had previously been treated for pediculiasis. The slope of the dose-response regression line for these lice did not differ significantly from zero (P = .66). This pediculicide immobilized lice sampled in Sabah. Mortality correlated closely with permethrin concentration (P = .008).

CONCLUSIONS

Head lice in the United States are less susceptible to permethrin than are those in Sabah. The pyrethroid susceptibility of the general population of head lice in the United States, however, remains poorly defined. Accordingly, these relatively safe over-the-counter preparations may remain the pediculicides of choice for newly recognized louse infestations.

Functional imaging predicts cognitive decline in Alzheimer's disease

Eighteen patients with Alzheimer's disease were studied with positron emission tomographic measurements of regional cerebral metabolism of glucose. All patients were initially diagnosed and evaluated, underwent positron emission tomography, and then were followed with annual reevaluations, at which time the Mini-Mental State Examination (MMSE) was performed. Patients were followed for an average of 2.5 years, and the rate of cognitive decline was calculated by determining the rate of change in the MMSE score defined as the MMSE score at the initial evaluation minus the MMSE score at the last examination, divided by the number of months between testing. The regional cerebral metabolic rates for glucose determined at the time of the first MMSE were then regressed on these changes in scores. Results showed that glucose metabolic rates in posterior temporal and primary visual cortex regions were significantly correlated with the subsequent rate of cognitive deterioration. These associations were not confounded by age, length of follow-up, baseline MMSE score, or education. Stratification on gender suggested that these associations were much stronger in women than in men. These results replicate previous findings showing that functional brain imaging is predictive of the rate of cognitive decline in Alzheimer's disease.

Temporal lobe perfusion on single photon emission computed tomography predicts the rate of cognitive decline in Alzheimer's disease

OBJECTIVE

To examine the ability of relative regional cerebral blood flow as measured by single photon emission computed tomography to predict longitudinal course of cognitive decline in Alzheimer's disease.

DESIGN

Single photon emission computed tomography using the blood flow tracer 123I-N-isopropyl-p-iodoamphetamine was performed at initial evaluation and was used to predict the rate of cognitive decline over a follow-up period from 1 to 4 years.

SETTING

Outpatient university dementia clinic and center for functional imaging.

PARTICIPANTS

Twenty-nine patients met National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for probably or possible AD.

RESULTS

Temporal lobe regional cerebral blood flow ratio at initial evaluation correlated with rate of decline in Mini-Mental State Examination over the longitudinal follow-up. Temporal regional cerebral blood flow ratio also predicted rate of decline of specific memory measures on the California Verbal Learning Test. Neither parietal nor frontal ratios predicted rate of cognitive decline. Dorsolateral frontal hypoperfusion was associated with the emergence of perseverative behaviors over time. Age, prior dementia duration, estimated prior rate of decline, and initial severity did not predict rate of cognitive decline.

CONCLUSION

Results suggest that regional perfusion on single photon emission computed tomography may predict cognitive decline in Alzheimer's disease better than these demographic and course variables.

Cross-Cultural Cognitive Examination performance in patients with Parkinson's disease and Alzheimer's disease

Performance profiles of patients with different dementia syndromes (Alzheimer's disease and Parkinson's disease) were compared with each other and with those of neurologically impaired and healthy individuals without dementia on a new instrument for screening dementia, the Cross-Cultural Cognitive Examination (CCCE). The CCCE measures discriminated reliably between nondemented and demented patients, regardless of etiology. Comparisons between dementia groups found that dementia patients with Parkinson's disease (PD) showed more severe psychomotor slowing and depression, compared with patients with Alzheimer's disease, who showed more impaired recall of recently learned verbal information and verbal abstract reasoning. The CCCE also distinguished between the motor and affective symptoms that are common to all PD patients and the dementia symptoms that occur in some PD patients. These results provide further support for the clinical utility of the CCCE for discriminating dementia from normal cognitive functioning and for initial identification of different dementia syndromes.

Cortical glucose metabolism in Parkinson's disease without dementia

There have been several reports of decreased regional cerebral metabolic rates for glucose (rCMRglc) in Parkinson's disease (PD), although others find no differences between PD patients and controls. Differences in the cognitive status of the PD patients may account for some of these inconsistencies. We report the results of a PET study using 18F-fluorodeoxyglucose (FDG) to measure rCMRglc in eight nondemented PD patients, six of whom were receiving dopaminergic medications, and eight age-matched control subjects. We scanned one tomographic level through the temporal lobes that included both temporal neocortex and mesial temporal cortex, and one tomographic level through the basal ganglia that included frontal and parietal cortex. Previously determined rate constants and an operational equation were used to determine rCMRglc. On average, rCMRglc values were 23% below control values for all regions studied, with the greatest differences in posterior brain regions (visual association cortex, primary visual cortex, and parietal cortex) and thalamus. These results indicate that PD patients may show neocortical hypometabolism, especially in posterior brain regions, in the absence of any demonstrable cognitive deficits.

Are multiple cerebral infarcts synergistic?

OBJECTIVE

The goal of this study was to characterize the cumulative effects of multiple strokes on cognition.

DESIGN

We conducted a prospective, longitudinal case study with neuropsychological, neurological, and radiological evaluations.

SETTING

Research was conducted at the Boston (Mass) Veterans Administration Medical Center, Neurology Service, on successive inpatient hospital admissions.

PATIENT

We followed up a 66-year-old right-handed man with multiple subcortical lacunae during a 3.5-year period during which he suffered two additional cortical infarctions.

MAIN OUTCOME MEASURES

Each evaluation included approximately 3 hours of neuropsychological testing spanning a range of cognitive domains (attention, language, memory, visuospatial functions, response inhibition, and mental flexibility), full neurological examination, and computed tomographic scan.

RESULTS

The patient's stepwise cognitive decline was characterized by unexpected exacerbation of "frontal" neurobehavioral features following the occurrence of two posterior cortical lesions. At initial evaluation, the computed tomographic scan showed bilateral subcortical lacunae in basal ganglia and periventricular white matter, and symptoms included dysarthria and perseveration. The second evaluation, following a left posterior parietal lesion, revealed a range of new frontal features, including impulsivity, pull-to-stimulus, and difficulty shifting set. Following a subsequent right occipital infarct, further frontal lobe impairments emerged: forced grasp reflex and incontinence.

CONCLUSIONS

We hypothesize that the cumulative effects of infarcts were synergistic. That is, the posterior cortical infarcts elicited frontal features that would not be expected from a simple sum of these lesions' effects.

Cross-cultural cognitive examination: validation of a dementia screening instrument for neuroepidemiological research

OBJECTIVE

Validation of a new instrument for screening dementia, the Cross Cultural Cognitive Examination (CCCE), is described.

DESIGN

Criterion and concurrent validation and cross-cultural comparison of a new instrument.

PARTICIPANTS

All individuals over the age of 40 in a village in southern Guam participated in a door-to-door survey. Alzheimer's and Parkinson's Disease patients and healthy controls aged 40-90 participated in the US mainland study.

MEASUREMENTS

The CCCE was administered to all subjects. Effects of age, language, education, and gender on test performances and social-cultural differences were assessed. Concurrent validation of the test with respect to other well accepted screening instruments was determined.

RESULTS

High specificity (> 94%) and sensitivity (> 99%) for detecting dementia were found in Guam and US mainland samples, and these were not biased by differences in gender, linguistic preference, education, or cultural background. Sensitivity and specificity of the CCCE matched or exceeded that of already accepted dementia screening instruments.

CONCLUSIONS

These validation studies support the usefulness of the CCCE for identifying patients with generalized dementia, rather than focal types of cognitive impairment, quickly and reliably in cross-cultural neuroepidemiological research.

Criterion validity of the cross-cultural cognitive examination in Japan

Criterion validity of a two-stage Cross-Cultural Cognitive Examination (CCCE) designed for epidemiologic use was evaluated in Japanese subjects by comparison with a physician's DSM-III-R diagnosis of dementia and the Hasegawa Dementia Rating Scale (the standard Japanese instrument similar to the Mini-Mental State Exam). We report on 188 subjects tested in three locations in Japan: Tokyo area, Ise, and Osaka. Subjects ranged in age (50-93 years) and education (1-22 years) and included neurology outpatients, community volunteers, and inpatients. The CCCE was 97.4% specific for dementia, with sensitivity of 88%. The correlation with the Hasegawa scale was significant (r(175) = .8230, p less than .0001). Diagnosis using the CCCE showed good validity when compared with Japanese criteria for dementia. If the instrument could be shown to be reliable and more "culture fair" than the currently available tests, it may be useful in cross-cultural epidemiologic studies of dementia.

Neuropsychological profile linked to low dopamine: in Alzheimer's disease, major depression, and Parkinson's disease

A distinct pattern of neuropsychological deficits was associated with low homovanillic acid (HVA) in the cerebrospinal fluid of 21 patients with: Alzheimer's disease (9), Parkinson's disease (8) and major depressive disorders (4). Regardless of clinical diagnosis, patients with low HVA were slower on a test of efficiency of processing timed information, and showed greater benefit from semantic structure on a verbal fluency task than patients with high HVA. However, low HVA subjects were not significantly impaired on confrontation naming (Boston Naming Test). Across three diagnostic groups, patients with lower HVA also tended to have more extrapyramidal motor signs and were significantly more depressed. These results demonstrate a significant relationship between specific neuro-behavioural deficits and dopaminergic activity which cuts across traditional diagnostic categories.

Cognitive changes in patients with multiple cerebral infarcts

Consensus has not been achieved regarding the impact of multiple cerebral infarcts on neurobehavioral status. To evaluate cognitive function in patients with multiple cerebral infarcts, we administered a comprehensive neuropsychological test battery to 23 consecutive male patients with clinical and brain computed tomographic findings consistent with at least two separate areas of cerebral infarction. Based on brain computed tomographic findings, patients were classified as having either mixed (n = 12) or lacunar (n = 11) infarcts. Results of these two groups were compared with those of 11 age-, sex-, and education-matched controls with no clinical or brain computed tomographic evidence of cerebrovascular disease. The mixed group had significantly lower mean scores than the controls for every cognitive domain tested. The lacune group showed cognitive impairment on most neuropsychological measures but did not differ from the controls in the attention domain. Although some degree of cognitive impairment was detected by the neuropsychological test battery in virtually every patient, only seven of 23 (30%) had Mini-Mental State Examination scores indicating dementia (less than 24). We conclude that virtually every patient with multiple cerebral infarcts has some degree of cognitive impairment but that only a minority can be classified as demented if the Mini-Mental State Examination is used as the primary defining examination.

Frontal systems impairment following multiple lacunar infarcts

To characterize cognitive impairments following multiple subcortical lacunar infarcts (lacunes), we prospectively compared the neuropsychological performance of 11 subjects with multiple lacunes with 11 medical control subjects matched for age and education who had no clinical or computed tomographic evidence of central nervous system disease. Subjects with multiple subcortical lacunes displayed neuropsychological signs of frontal system dysfunction, even though only 27% met the criteria for clinical diagnosis of dementia. They exhibited significant deficits in shifting mental set, response inhibition, and executive function. In addition, they were more often rated apathetic on a behavior-rating scale. We propose a continuum of cognitive impairments in lacunar states, ranging from frontal systems impairment to dementia.

Alpha 2-adrenergic receptor sensitivity in depressed patients: relation between 3H-yohimbine binding to platelet membranes and clonidine-induced hypotension

Alpha 2-adrenergic receptor changes during antidepressant treatment were studied using 3H-yohimbine binding to human platelet membranes and clonidine-induced hypotension. Twenty-six patients with major depressive disorder (MDD) participated for 4-6 weeks in a trial of imipramine (2.5 mg/kg/day), tyrosine (100 mg/kg/day), or placebo. Alpha 2-adrenergic receptors measured by 3H-yohimbine binding were not significantly changed following antidepressant treatment. Similarly, clonidine-induced hypotension did not differ significantly following treatment. No measure of alpha 2-adrenergic receptor sensitivity was significantly correlated with clinical improvement. The correlation between platelet receptor binding and clonidine-induced hypotension was not statistically significant, even though both tests are considered to be measures of alpha 2-adrenoceptor sensitivity.

Alpha-melanocyte-stimulating hormonelike immunoreactivity is increased in cerebrospinal fluid of patients with Parkinson's disease

We measured alpha-melanocyte-stimulating hormonelike immunoreactivity in cerebrospinal fluid of 12 healthy control subjects and nine patients with Parkinson's disease, four of whom had never been treated. Mean cerebrospinal fluid alpha-melanocyte-stimulating hormonelike immunoreactivity concentration was two-fold greater in parkinsonian patients (44.1 +/- 9.3 [SD] pg/mL) as compared with control subjects (21.8 +/- 10.0 pg/mL). No significant correlation was found between cerebrospinal fluid alpha-melanocyte-stimulating hormonelike immunoreactivity concentrations and patient age, disease severity, or duration of disease. These results suggest a functional relation between dopaminergic and melanotropinergic systems in the human brain.

Alpha 2-adrenergic receptors in platelet membranes of depressed patients: increased affinity for 3H-yohimbine

Specific binding to alpha 2-adrenergic receptors was studied in the platelets of 31 patients with major depressive disorder and 18 normal controls using the selective antagonist 3H-yohimbine. Receptor density for depressed patients (Bmax = 88 +/- SD 45.1 fmoles/mg) was not significantly lower than that for controls (124 +/- SD 78.1 fmoles/mg). The affinity of the receptor for yohimbine was significantly greater in depressed patients (Kd = 1.05 +/- SD 0.47 nM) than in controls (Kd = 1.47 +/- SD 0.63 nM). This is consistent with the hypothesis of increased alpha 2-adrenergic receptor sensitivity in depressive disorders. Past studies of alpha 2-adrenergic receptors on platelets are reviewed, and the importance of designing studies with sufficient statistical power is discussed.

Recovery in major depressive disorder: analysis with the life table and regression models

Regression models and life tables were used to describe the phenomenon of recovery from major depressive disorder for 101 patients in a naturalistic study in which treatment was not controlled by the investigators. Time to recovery from the onset of the episode was protracted, as only about 50% of patients recovered by one year. Annual rates of recovery then declined steadily to 28% in the second year, 22% in the third year, and 18% in the fourth year. In contrast, speed of recovery from entry into the study was more rapid, and 63% of patients recovered by four months. The recovery rates were about 20% each month for the first four months and then declined sharply for the remaining months of the one-year follow-up. Several clinical variables were statistically significant predictors of recovery when measured from entry into the study: superimposition of the acute episode on a chronic underlying depression, acuteness of onset of he depression, and severity of depression for the subgroup of patients without superimposed illness.

Relapse in major depressive disorder: analysis with the life table

With the use of life tables to describe time while patients were well and subsequent rates of relapse for 75 patients after their recovery from an episodes of major depressive disorder in naturalistic study, a high risk of relapse was detected shortly after recovery. Twenty-four percent of patients relapsed within 12 weeks at risk, and 12% of patients relapsed with four weeks at risk. The presence of an underlying chronic depression and three or more previous affective episodes predicted a statistically significant increase in the rate of relapse. These data were used to develop an exponential model of relapse probability for a subgroup of the study population.