[Late-life depression and frailty-Epidemiological, clinical and neurobiological associations]

BACKGROUND

Depression is the most common mental disorder in older adults and is influenced by age-related processes. Frailty is a well-established clinical expression of ageing that implies a state of increased vulnerability to stressor events as well as increased risks of disability, hospitalization and death. Neurobiological findings will disentangle the comorbidity of frailty and depression and may inform future management of depression in old age.

OBJECTIVE

This narrative review provides an overview of the comorbidity of late-life depression and frailty, with a focus on neuroscientific findings that are organized within the research domain criteria (RDoC) framework.

RESULTS

More than one third of old people with depression are affected by frailty, which results in more chronic depression and in poorer efficacy and tolerability of antidepressant medication. Depression and frailty share motivational and psychomotor characteristics, particularly apathy, decreased physical activity and fatigue. In patients with frailty, altered activity of the supplementary motor cortex is associated with motor performance deficits. Patients with late-life depression and apathy are characterized by abnormal structure and altered functional connectivity of the reward network and the salience network, along with altered functional connectivity of these networks with premotor brain areas.

CONCLUSION

Identifying frailty in older adults with depression is relevant for prognostic assessment and treatment. A better understanding of the neuronal mechanisms of comorbidity will provide potential targets for future personalized therapeutic interventions.

One Atom Makes All the Difference: Getting a Foot in the Door between SOS1 and KRAS

KRAS, the most common oncogenic driver in human cancers, is controlled and signals primarily through protein-protein interactions (PPIs). The interaction between KRAS and SOS1, crucial for the activation of KRAS, is a typical, challenging PPI with a large contact surface area and high affinity. Here, we report that the addition of only one atom placed between Y884^SOS1 and A73^KRAS is sufficient to convert SOS1 activators into SOS1 inhibitors. We also disclose the discovery of BI-3406. Combination with the upstream EGFR inhibitor afatinib shows in vivo efficacy against KRAS^G13D mutant colorectal tumor cells, demonstrating the utility of BI-3406 to probe SOS1 biology. These findings challenge the dogma that large molecules are required to disrupt challenging PPIs. Instead, a "foot in the door" approach, whereby single atoms or small functional groups placed between key PPI interactions, can lead to potent inhibitors even for challenging PPIs such as SOS1-KRAS.

Structure of the helicase core of Werner helicase, a key target in microsatellite instability cancers

Loss of WRN, a DNA repair helicase, was identified as a strong vulnerability of microsatellite instable (MSI) cancers, making WRN a promising drug target. We show that ATP binding and hydrolysis are required for genome integrity and viability of MSI cancer cells. We report a 2.2-Å crystal structure of the WRN helicase core (517-1,093), comprising the two helicase subdomains and winged helix domain but not the HRDC domain or nuclease domains. The structure highlights unusual features. First, an atypical mode of nucleotide binding that results in unusual relative positioning of the two helicase subdomains. Second, an additional β-hairpin in the second helicase subdomain and an unusual helical hairpin in the Zn2+ binding domain. Modelling of the WRN helicase in complex with DNA suggests roles for these features in the binding of alternative DNA structures. NMR analysis shows a weak interaction between the HRDC domain and the helicase core, indicating a possible biological role for this association. Together, this study will facilitate the structure-based development of inhibitors against WRN helicase.

Structure of McsB, a protein kinase for regulated arginine phosphorylation

Protein phosphorylation regulates key processes in all organisms. In Gram-positive bacteria, protein arginine phosphorylation plays a central role in protein quality control by regulating transcription factors and marking aberrant proteins for degradation. Here, we report structural, biochemical, and in vivo data of the responsible kinase, McsB, the founding member of an arginine-specific class of protein kinases. McsB differs in structure and mechanism from protein kinases that act on serine, threonine, and tyrosine residues and instead has a catalytic domain related to that of phosphagen kinases (PhKs), metabolic enzymes that phosphorylate small guanidino compounds. In McsB, the PhK-like phosphotransferase domain is structurally adapted to target protein substrates and is accompanied by a novel phosphoarginine (pArg)-binding domain that allosterically controls protein kinase activity. The identification of distinct pArg reader domains in this study points to a remarkably complex signaling system, thus challenging simplistic views of bacterial protein phosphorylation.

Test-retest reliability and minimal detectable change of repeated sit-to-stand analysis using one body fixed sensor in geriatric patients

A majority of geriatric patients experience difficulty in performing sit-to-stand (SiSt) transitions. A detailed assessment of SiSt ability is a prerequisite for successful rehabilitation. Body fixed sensors (BFSs) are increasingly used to assess functional performances. As to date there is no system which analyzes clinically relevant phases of SiSt, the aim of this study was to determine the reliability of an automated approach for quantifying durations and angular velocities of trunk flexion and extension during repeated SiSt transitions using one BFS (DynaPort® Hybrid). Forty multimorbid geriatric patients aged 84.1 ± 6.6 years were included. Each patient participated in two test sessions with a 5 min rest period in between. Intra- and interrater reliability was assessed. Intraclass correlation coefficients (ICCs), absolute and relative standard measurement errors (SEMs, SEMs%) and minimal detectable changes (MDCs(95), MDCs(95)%) were calculated. ICCs were good to excellent for all variables in the total sample (0.80-0.94). The intraobserver group (50%) showed a higher number of excellent ICCs (≥.9) compared to the interobserver subgroup (10%). SEM% was low for all variables (6.9-12.7%). MDC(95)% ranged 19.2-34.4% and more variables ≤30% were found in the intra- (80%) compared to the inter-observer group (60%). Study results demonstrate that the BFS system provides a reliable analysis of SiSt phases in geriatric patients, and is a substantial improvement over the stopwatch approach used in clinical practice today.

Validation of the Falls Efficacy Scale and Falls Efficacy Scale International in geriatric patients with and without cognitive impairment: results of self-report and interview-based questionnaires

BACKGROUND

Frail, old patients with and without cognitive impairment are at high risk of falls and associated medical and psychosocial issues. The lack of adequate, validated instruments has partly hindered research in this field. So far no questionnaire documenting fall-related self-efficacy/fear of falling has been validated for older persons with cognitive impairment or for different administration methods such as self-report or interview.

OBJECTIVE

To validate the self-report and interview version of the Falls Efficacy Scale (FES) and the Falls Efficacy Scale International Version (FES-I) in frail geriatric patients with and without cognitive impairment.

METHODS

156 geriatric patients in geriatric rehabilitations wards with (n = 75) and without cognitive impairment (n = 81) were included in this study. Reports of fall-related self-efficacy were based on self-reported and interview-based questionnaires. Descriptive statistics, reliability estimates and validation results were computed for the total group and sub-samples with respect to cognitive status, for the 2 different questionnaires (FES/FES-I) and for the 2 administration methods. Test-retest reliability was tested in a subsample of 62 patients.

RESULTS

Internal reliability and test-retest reliability were good to excellent in both the FES and FES-I, with the FES-I showing better internal reliability and the FES better test-retest reliability with respect to cognitively impaired persons. The group of cognitively impaired persons tended to show lower test-retest reliability and mean fall-related self-efficacy and had significantly lower completion rates in self-administered questionnaires. As indicated by significant differences in parameters closely related to falls, such as vertigo, functional performances, fear of falling and history of falls, both the FES and the FES-I showed good construct validity. Effect sizes computed for the above-mentioned groups for fall-related parameters confirmed the results of construct validation.

CONCLUSION

Both the FES as well as the FES-I showed good to excellent measurement properties in persons with and without moderate cognitive impairment. In frail older persons, especially in persons with cognitive impairment, an interview-based administration method is recommended.

Distance to achieve steady state walking speed in frail elderly persons

This study aims to determine the length of the gait initiation phase before achieving steady state walking in frail older people. Based on body fixed sensors, habitual walking was analysed in 116 community-dwelling older persons (mean age 83.1 years, 84% women). The start of steady state walking was identified using an algorithm taking into account speeds from consecutive strides. On average, participants reached a walking speed of 0.66 m/s after an acceleration phase of 1.43 m (89% after 2.47 m). When spatio-temporal variables were calculated from 4, 6, 8, 10, or 20 consecutive stride cycles after achieving steady state, similar values were observed for mean gait speed and stride length. The variability of these factors differed depending on the number of gait cycles. Assessments of steady state gait in frail elderly people should therefore exclude the first 2.5m of walking. If gait variability is to be assessed, it is recommended that more than 20 stride cycles be used.

Recommendations for promoting the engagement of older people in activities to prevent falls

OBJECTIVE

To develop recommendations for promoting uptake of and adherence to falls-prevention interventions among older people.

DESIGN

The recommendations were initially developed from literature review, clinical experience of the core group members, and substantial qualitative and quantitative studies of older people's views. They were refined through a consultation process with members of the falls-prevention community, drawing on Delphi survey and nominal group techniques. Transparency was enhanced by recording and reporting aspects of the iterative consultation process such as the degree of consensus and critical comments on drafts of the recommendations.

SETTING

The recommendations were developed and refined at three meetings of the core group, and through internet-based consultation and two meetings involving members of the wider falls-prevention community.

PARTICIPANTS

The authors developed the recommendations incorporating the feedback from the researchers and practitioners responding to a broad-based internet consultation and consulted in the meetings.

RESULTS

A high degree of consensus was achieved. Recommendations addressed the need for public education, ensuring that interventions were compatible with a positive identity, tailoring interventions to the specific situation and values of the individual, and using validated methods to maintain longer-term adherence.

CONCLUSION

These recommendations represent a consensus based on current knowledge and evidence, but the evidence base from which these recommendations were developed was limited, and not always specific to prevention of falls. To increase the effectiveness of falls-prevention interventions, further research is needed to identify the features of falls-prevention programmes that will encourage older people's engagement in them.

[The German version of the Falls Efficacy Scale-International Version (FES-I)]

The German version of the Falls Efficacy Scale-International Version (FES-I), which is presented, was developed for the documentation of fall-related selfefficacy in older persons by a EU-funded expert network (Prevention of Falls Network Europe ProFaNE). The FES-I represents a modification of the original Falls Efficacy Scale (FES), including additional items on complex functional performances and social aspects of falls. The FES-I shows high internal reliability (Cronbach's alpha = 0.96) as well as high test-retest reliability (r=0.96). The mean inter-item correlation was: r = 0.55 (Range r = 0.29-0.79). Results of validation studies for the FES-I in community dwelling older persons for different European countries and geriatric patients with cognitive impairment will be published in the near future.

Effectiveness of Physical Training on Motor Performance and Fall Prevention in Cognitively Impaired Older Persons

OBJECTIVE

To determine whether older cognitively impaired people benefit from physical training with regard to motor performance or fall risk reduction and to critically evaluate the methodologic approach in identified randomized controlled intervention trials.

DESIGN

Published randomized controlled intervention trials from 1966 through 2004 were identified in PubMed, CINAHL, Gerolit, and the Cochrane Central Register of Controlled Trials according to predefined inclusion criteria and evaluated by two independent reviewers using a modified rating system for randomized controlled intervention trials developed by the Cochrane Library.

RESULTS

There were 11 randomized controlled intervention trials that met the predefined inclusion criteria. There was a large heterogeneity regarding methodology, sample size, type of intervention, study outcomes, and analyses. We found conflicting evidence regarding the effect of physical training on motor performance and falls in older people with cognitive impairment. However, a considerable number of the studies had methodologic limitations, which hampered the evaluation of the effectiveness of training.

CONCLUSIONS

The randomized controlled intervention trials showed only limited effectiveness of physical training in patients with cognitive impairment. More studies with adequate sample size, sensitive and validated measurements, and higher specificity for the types of intervention targeting subgroups of patients with different degrees of cognitive impairment are required to give evidence-based recommendations.

[Physical exercise in old age]

For the prevention of diseases and especially functional deficits in old age, physical activity is a simple, practicable and successful method. With increasing age and frailty or in rehabilitation training, these activities have to be more and more individualized and medically supervised. The paper defines from today's viewpoint suitable activities and the amount of training necessary. Finally, the need for research about physical training in geriatric medicine is pointed out.

Zufriedenheit geriatrischer Patienten mit ihrer Schmerztherapie

AIM

The goal of this study was to determine the level of satisfaction of geriatric patients with their pain therapy, their wishes for improved treatment, and possible influencing factors.

METHODS

From April to November 2002, all patients able to communicate ( n=1432) were included in the study if they had reported pain in the previous 7 days or were taking regular analgesic medication without specifying pain.

RESULTS

Of the geriatric patients reporting from home, 36.4% were not satisfied with their pain therapy up to that time, and 25.4% of surgical patients were dissatisfied as were 28.5% of patients treated in other departments. A total of 93.3% desired better pain treatment. Independent predictors for dissatisfaction with their therapy or wish for improvement were increasing pain intensity, frequent concomitant complaints in addition to pain, and the objectively perceived everyday competence.

CONCLUSION

This study supports the observation that competent pain therapy is necessary and that there is room for improvement in geriatric facilities. Measuring pain intensity, posing questions pertaining to satisfaction with pain therapy, and determining whether patients desire better pain treatment are all indispensable for optimal care. Pain therapy should equally address reduction of pain intensity and management of other complaints.

[Problems recognizing pain in geriatrics]

OBJECTIVE

Elderly people often present substantial problems in pain assessment. The aim of the study was to quantify and discuss the problem of recognizing pain in hospitalized geriatric patients.

METHODS

124 geriatric patients and their treating doctors were questioned about pain, pain intensity and influence of pain on daily living in a cross-sectional-study. The score of the Barthel index (activity of daily living, ADL) at admittance and discharge, the cognitive status (monumental status of Folstein, MMS), the use of analgetic drugs and the medical diagnoses were assessed. The answers of the question "Did you/your patient have pain in the past seven days?" from patients and doctors were used to make seven groups.

RESULTS

20 (16,1%) patients could not answer the question about pain. In comparison to the group of patients who were able to answer, they were restricted in ADL and MMS. However, the answers of doctors about pain did not differ. 25 (20,3%) answers of treating doctors were wrong compared to the answers of the patients. In these cases, intensity and influence of pain on daily living were estimated low by the patients. In 14 (11,3%) patients, doctors could not state about pain. These patients were least restricted in ADL at admission and discharge. Altogether, the pain of 13/46 (28,3%) patients was treated insufficiently at the day of the interview.

CONCLUSIONS

In half of the geriatric patients, pain was not well or not at all recognized by the treating doctors. Pain of not communicative patients was assessed similarly by the doctor as that of patients who were able to give information. In this geriatric hospital, little support at admittance and a superior improvement in the activities of daily living during the in-hospital treatment lead to less attention to pain by the doctor. The importance of pain therapy in geriatrics is illustrated by the fact that almost every third patient with pain is treated insufficiently at the day of the interview.

Plasma cystine concentration and redox state in aging and physical exercise

Because redox-regulated signalling pathways are often modulated by the thiol/disulfide redox state (REDST), changes in plasma REDST may possibly account for pathological processes. We, therefore, investigated the mechanisms that account for changes in the plasma REDST as derived in first approximation from the cystine and acid soluble thiol (mainly cysteine) concentrations. Elderly subjects (studies A) and younger subjects after intensive physical exercise (IPE) (study B) i.e. subjects in conditions typically associated with decreased insulin responsiveness, showed, on the average, an increase in the plasma total free amino acid (TAA) concentration to approximately 3000 microM, including an increase in cystine but no increase in the thiol concentration if compared with controls. The REDST was decreased accordingly. A study on the postabsorptive amino acid exchange rates across the lower extremities (study C) indicated that a TAA level > or =2800 microM supports a balanced net protein synthesis even under conditions of weak insulin stimulation, suggesting that high TAA levels may prevent the release of cysteine into the blood in the postabsorptive state. Collectively, these studies indicate that the age-related oxidative shift in plasma REDST may result from the decrease in amino acid clearance capacity and may be aggravated by excessive physical exercise.

[Recognizing pain in geriatric patients by an interdisciplinary team. Reliability of judgment and factors of influence]

The prevalence of chronic pain increases with age. The awareness of pain in geriatric patients is more difficult than in younger people because of various reasons. The occupational groups of the geriatric team might be different in respect of discerning symptoms of pain. 126 geriatric patients were enrolled in this study. They were asked if they had pain today and in the last seven days. At the same time the members of the geriatric team (old people's nurses, nurses, physicians, physio-, occupational and speech therapists) were asked the same questions with respect of their patients. Items possible influencing the answers were recorded: patient's characteristics: age, cognition (Folstein's minimental state) and duration of hospital stay before this interview; employee's characteristics: age, days of care in the past 7 days, weekly working hours, occupational years and years working in this geriatric hospital. The judgement of the geriatric team varied widely. It was dependent on the profession, days of care, weekly working hours and professional experience. Changes of care in the last 7 days have an negative effect in all occupational groups. Other features will be discussed in details. The handing of the patient's pain should be improved within the occupational groups.

Exercise training for rehabilitation and secondary prevention of falls in geriatric patients with a history of injurious falls

OBJECTIVE

To determine the safety and efficacy of an exercise protocol designed to improve strength, mobility, and balance and to reduce subsequent falls in geriatric patients with a history of injurious falls.

DESIGN

A randomized controlled 3-month intervention trial, with an additional 3-month follow-up.

SETTING

Out-patient geriatric rehabilitation unit.

PARTICIPANTS

Fifty-seven female geriatric patients (mean age 82 +/- 4.8 years; range 75-90) admitted to acute care or inpatient rehabilitation with a history of recurrent or injurious falls including patients with acute fall-related fracture.

INTERVENTION

Ambulatory training of strength, functional performance, and balance 3 times per week for 3 months. Patients of the control group attended a placebo group 3 times a week for 3 months. Both groups received an identical physiotherapeutic treatment 2 times a week, in which strengthening and balance training were excluded.

MEASUREMENTS

Strength, functional ability, motor function, psychological parameters, and fall rates were assessed by standardized protocols at the beginning (T1) and the end (T2) of intervention. Patients were followed up for 3 months after the intervention (T3).

RESULTS

No training-related medical problems occurred in the study group. Forty-five patients (79%) completed all assessments after the intervention and follow-up period. Adherence was excellent in both groups (intervention 85.4 +/- 27.8% vs control 84.2 +/- 29.3%). The patients in the intervention group increased strength, functional motor performance, and balance significantly. Fall-related behavioral and emotional restrictions were reduced significantly. Improvements persisted during the 3-month follow-up with only moderate losses. For patients of the control group, no change in strength, functional performance, or emotional status could be documented during intervention and follow-up. Fall incidence was reduced nonsignificantly by 25% in the intervention group compared with the control group (RR:0.753 CI:0.455-1.245).

CONCLUSIONS

Progressive resistance training and progressive functional training are safe and effective methods of increasing strength and functional performance and reducing fall-related behavioral and emotional restrictions during ambulant rehabilitation in frail, high-risk geriatric patients with a history of injurious falls.

Myocardial ischemia during physical exercise in patients with stable coronary artery disease: predictability and prevention

AIMS

We assessed whether exercise-induced myocardial ischemia during intensive group exercise sessions can be predicted in patients with coronary artery disease and stable angina pectoris.

METHODS AND RESULTS

Twenty-three patients underwent cardiac catheterization, 201-thallium scintigraphy, and exercise testing prior to participation in group training sessions. Heart rates and myocardial ischemia were documented by Holter monitoring. The individual training heart rate was calculated as a percentage of the maximal heart rate achieved during symptom-limited exercise testing. Myocardial ischemia occurred significantly more often during group exercise sessions (15 of 23 patients) than during treadmill testing (4 of 23 patients, P<0.001). Maximal heart rate (145+/-23 vs. 134+/-21 beats/min, P<0.004) and maximal plasma lactate concentrations (6.0+/-2.9 vs. 4.3+/-2.0 mmol/l, P<0.05) were significantly higher than during symptom-limited exercise testing. Ischemic episodes occurred significantly more often during jogging than during competitive ball games or interval training. Myocardial ischemia occurred in patients who exceeded their individual target training heart rates (43 of 44 episodes; P<0.001). Duration of ischemic episodes did not correlate with any marker obtained at the beginning of the study.

CONCLUSION

These data demonstrate that routine diagnostic procedures do not sufficiently identify patients at risk for exercise-induced myocardial ischemia. Ischemic events are only effectively prevented by choosing adequate types of exercise and, above all, by the strict adherence to individual target heart rates.

Functional impact of an increase in ventricular mass after myocardial damage and its attenuation by converting enzyme inhibition

BACKGROUND

A increase in left ventricular mass after ventricular damage has been identified as an initial response to injury. However, the functional significance of this response has not been clearly established and is the focus of this study.

METHODS AND RESULTS

Twelve mongrel dogs underwent transmyocardial direct current shock to produce transmural left ventricular damage. Six were assigned to converting enzyme inhibitor therapy initiated 24 hours after damage and continued for 4 weeks. The remaining six dogs served as a control group. Left ventricular structure (mass and end diastolic volume) and systolic function (regional and global ejection fraction at rest and during afterload stress) were assessed by magnetic resonance imaging before damage and at the end of the 4-week period. After myocardial damage, left ventricular mass increased from 93.6 +/- 4.0 to 107.5 +/- 3.4 gm in the control group (P < .01) with no change in ventricular volume. Ramipril-treated dogs displayed a reduction in mass (83.2 +/- 2.2 to 74.6 +/- 2.9 gm, P < .05). In the control group, there was greater reduction in global ejection fraction in response to afterload stress at 4 weeks compared with baseline (-16 +/- 4 vs -4 +/- 3%, P = .03). Ejection fraction response to afterload stress was maintained at 4 weeks in the converting enzyme inhibitor-treated group (-5 +/- 3 vs - 1 +/- 4%) and was different at 4 weeks from the control group (-1 +/- 4 vs -16 +/- 4%, P = .004).

CONCLUSION

The increase in left ventricular mass noted after direct current shock was associated with the impairment of systolic function during afterload stress. Inhibition of this mass increase results in preservation of function, thus further supporting the concept that attenuation of ventricular remodeling should be a therapeutic goal.

Activation of coagulation and fibrinolysis after rehabilitative exercise in patients with coronary artery disease

It has been suggested that blood coagulation be activated and fibrinolytic activity be impaired in patients with coronary artery disease (CAD). With regard to the activation of coagulation and fibrinolysis occurring during exercise in healthy individuals, we examined the hypothesis that rehabilitative exercise in patients with CAD might give rise to an exaggerated activation of coagulation. In 12 patients with angiographically documented CAD without myocardial infarction within the preceding 6 months (male, age 55+/-9 years [SD]) and in 12 healthy controls (male, 52+/-7 years), molecular markers of thrombin, fibrin, and plasmin formation were determined before and after a rehabilitative group exercise session lasting 1 hour. Resting levels of prothrombin fragment 1+2 were lower in patients with CAD (0.67+/-0.2 [SE] vs 1.04+/-0.2 nmol/L, p <0.001) and remained unchanged after exercise, whereas a significant increase was noted in controls (p <0.01). After exercise, plasma levels of thrombin-antithrombin III complexes and of fibrinopeptide A increased significantly in both groups, although there were more pronounced changes in controls. Exercise resulted in a marked generation of plasmin as indicated by plasmin-alpha2-antiplasmin complexes increasing 2.5-fold in patients (p <0.001) and threefold in controls (p <0.001). Repeated experiments in control subjects after administration of aspirin (day 1: 500 mg; days 2 to 5: 100 mg) documented that differences between groups could not be attributed to aspirin medication (100 mg/day) in patients with CAD. We concluded that rehabilitative exercise in patients with CAD beyond the immediate postinfarction period has no detrimental effects on thrombin, fibrin, and plasmin formation.

Effect of delayed intervention with ACE-inhibitor therapy on myocyte hypertrophy and growth of the cardiac interstitium in the rat model of myocardial infarction

The effectiveness of angiotensin-converting enzyme (ACE)-inhibitor therapy in attenuating ventricular remodeling when initiated immediately following myocardial damage is clearly established. Less information, however, is available on the impact of late therapy on the remodeling process, especially its influence on the cellular components of these structural changes. The purpose of this study was to examine the effects of converting enzyme inhibitor therapy commenced 28 days following infarction in the rat on changes in cardiac myocyte dimension and the interstitium. At 28 days following infarction, myocyte cell length (153.9+/-7.3 v 131.1+/-5.9 micron, P=0.0002) and cell volume in the free wall of the left ventricle (38. 5+/-5.0 x 10(3) v31.4+/-3.1 x 10(3), P=0.009) had increased compared with sham-operated rats. Similar changes were noted in the septum and right ventricle. Captopril therapy administered between 28 and 56 days attenuated a further increase in cell length noted in an untreated group in the left ventricle (153.5+/-15.3 v 167.3+/-13.7 micron, P=0.02), right ventricle (153.8+/-20.5 v 173.8+/-2.3 micron, P=0.01) and septum (158.0+/-20.2 v 179.1+/-16.6 micron, P=0.004). There was an increase in hydroxyproline content in the right ventricle and a similar trend in the left ventricle in the untreated myocardial infarction groups. These changes were not altered by captopril therapy. In summary, even late therapy with captopril attenuates progressive myocyte remodeling, which may contribute to the ability of ACE-inhibitor therapy to slow progressive chamber enlargement following infarction.

The effect of delayed reperfusion following infarction in the rat on structural changes in viable myocardium

OBJECTIVE

Evidence indicates that patency of the infarct related artery following the completion of myocardial necrosis can attenuate ventricular remodeling. Data have also demonstrated that inhibition of infarct expansion contributes to the anti-remodeling effect of delayed reperfusion. However, the influence of a patent artery on components of the remodeling process in the viable myocardium is poorly understood.

METHODS

Myocyte morphometrics (isolated cell technique) and collagen content (hydroxyproline analysis) were assessed 28 days following experimental myocardial infarction from rats with permanently ligated left coronary vessels (NRP; n = 10) compared with rats who underwent reperfusion 150 minutes after ligation (RP; n = 11) and a sham-operated group (n = 10).

RESULTS

Analysis of infarct size (planimetry) in a separate group of rats demonstrated that reperfusion at this late time point did not reduce infarct size (NRP: 33 +/- 3 vs. RP: 35 +/- 5%). Myocyte length in RP rats was less than in NRP rats in viable, non-infarcted left ventricular tissue (155 +/- 3 vs. 167 +/- 4 microns, p = 0.02), in the right ventricle (154 +/- 4 vs. 167 +/- 3 microns, p = 0.02) and in the septum (158 +/- 4 vs. 169 +/- 4 microns, p = 0.05). Reperfusion also attenuated the expected increase in cell volume compared with NRP rats (left ventricle 39.4 +/- 1.7 x 10(3) vs. 44.1 +/- 1.6 x 10(3) micron 3, p = 0.06; right ventricle 36.7 +/- 1.6 x 10(3) vs. 42.7 +/- 2.0 x 10(3) micron 3, p = 0.02; septum 41.0 +/- 1.6 x 10(3) vs. 44.2 +/- 1.8 x 10(3) micron 3, p = 0.19). Hydroxyproline content increased in the viable left ventricular tissue in both the reperfused and non-reperfused groups.

CONCLUSION

Reperfusion without myocardial salvage attenuates the increase in myocyte length and volume that occurs in remodeling myocardium following infarction in the rat, with no effect on the increase in collagen content. These data indicate that patency of the infarct vessel, which is known to have an inhibitory effect on infarct expansion, also has an anti-remodeling effect remote from the area perfused by this artery.

Attenuated progression of coronary artery disease after 6 years of multifactorial risk intervention: role of physical exercise

BACKGROUND

It was the aim of this study to assess the long-term effects of physical exercise and low-fat diet on the progression of coronary artery disease. At the beginning of the study, 113 male patients with coronary artery disease were randomized to an intervention group (n=56) or a control group (n=57); 90 patients (80%) could be reevaluated after 6 years.

METHODS AND RESULTS

Patients in the intervention group (n=40) showed a reduction in total serum cholesterol (6.03+/-1.03 versus 5.67+/-1.01 mmol/L; P<.03) and triglyceride levels (1.94+/-0.8 versus 1.6+/-0.89 mmol/L; P<.005) and maintained their initial body mass index (26+/-2 versus 27+/-2 kg/m2; P=NS), but results were not statistically different from the control group (n=50) (total serum cholesterol, 6.05+/-1.02 versus 5.79+/-0.88 mmol/L; triglycerides, 2.25+/-1.28 versus 1.85+/-0.96 mmol/L [both P=NS]; body mass index, 26+/-2 versus 28+/-3 kg/m2 [P<.0001]). In the intervention group, there was a significant 28% increase in physical work capacity (166+/-59 versus 212+/-89 W; P<.001), whereas values remained essentially unchanged in the control group (165+/-51 versus 170+/-60 W; P=NS; between groups, P<.05). In the intervention group, coronary stenoses progressed at a significantly slower rate than in the control group (P<.0001). Energy expenditure during exercise was assessed in a subgroup; patients with regression of coronary stenoses spent an average of 1784+/-384 kcal/wk (approximately 4 hours of moderate aerobic exercise per week). Multivariate regression analysis identified only physical work capacity as independently contributing to angiographic changes.

CONCLUSIONS

After 6 years of multifactorial risk intervention, there is significant and persistent improvement in lipoprotein levels and physical work capacity, which results in a significant retardation of disease progression. These beneficial effects appear to be largely due to chronic physical exercise.

[Strength and coordination training for prevention of falls in the elderly]

Since muscle strength and coordination training in healthy elderly people has been effective in the primary prevention, a program for geriatric patients with falls is presented. Its aim is safer walking by an increase in muscular strength and improved coordination. The exclusion criteria and the size of the training program define a group of over 75 year old patients, who will be compared with a group with light physical exercise in a randomized fashion. The first results show a remarkable increase in strength and a low complication rate. The functional relevance of our program remains to be proven.

Predictive value of lipid profile for salutary coronary angiographic changes in patients on a low-fat diet and physical exercise program

In this study, 113 patients with modestly elevated levels of low-density lipoprotein cholesterol (<210 mg/dl) and coronary artery disease were randomized to an intervention group (n=56) or a control group (n=57). The intervention program consisted of daily exercise and a low-fat diet according to the American Heart Association's recommendation phase III; patients in the control group received "usual care" rendered by their private physician. After 1 year, complete data were available for all 92 patients (intervention: n=40; control: n=52) who underwent repeat coronary angiography. During the study course, patients in the intervention group showed an increase in apolipoprotein A-I(123 +/- 18 vs 129 +/- 20 mg/dl; p < 0.02) and apolipoprotein A-I/B (1.3 +/- 0.4 vs 1.5 +/- 0.4; p <0.01) and a decrease in apolipoprotein B (99 +/- 20 vs 89 +/- 18 mg/dl; p < 0.01), while apolipoprotein A-II remained unchanged (38 +/- 6 vs 38 +/- 6 mg/dl; p=NS). In the control group, there were no significant changes (apolipoprotein A-I, 124 +/- 17 vs 128 +/- 13 mg/dl; apolipoprotein A-II, 38 +/- 6 vs 39 +/- 6 mg/dl; apolipoprotein B, 100 +/- 21 vs 99 +/- 16 mg/dl; apolipoprotein A-I/B, 1.3 +/- 0.3 vs 1.4 +/- 0.5; all p=NS). As previously reported, there was a significant retardation of progression in patients in the intervention group (progression 23%, no change 45%, regression 32%) compared with the control group (progression 48%, no change 35%, regression 17%) (p < 0.05). Although retardation of progression was significantly associated with an increase in apolipoprotein A-I/B and a decrease in apolipoprotein B (p < 0.05), these gave way in multivariate analysis to changes in total cholesterol/high-density lipoprotein cholesterol, absolute levels of low-density lipoprotein cholesterol, and, in a subgroup of patients, to leisure-time physical activity (all p < 0.05). These data demonstrate that an intervention based on a low-fat diet and intensive physical exercise is capable of improving apolipoprotein levels, associated with retardation of progression of coronary artery disease. However, total cholesterol/high-density lipoprotein cholesterol and low-density lipoprotein cholesterol appear superior to apolipoproteins as metabolic markers for effective treatment in patients with coronary artery disease.

Impact of intensive physical exercise and low-fat diet on collateral vessel formation in stable angina pectoris and angiographically confirmed coronary artery disease

This randomized study was performed to assess the effects of > 3 hours of physical exercise per week and low-fat diet on collateral formation in nonselected patients with coronary artery disease (intervention group, n = 56). Results were compared with those of patients in a control group (n = 57), who received usual care by their private physicians. Coronary lesions were assessed by quantitative coronary angiography at the beginning and after 1 year of study (n = 92). As previously reported, after 1 year there was a significant retardation of progression of coronary artery disease in the intervention group as compared with the control group. In this study, evaluation of collateral formation revealed no significant difference between both groups, and changes in hemodynamic and metabolic variables or leisure time physical activity were not related to changes in collateral formation. Although progression of the disease was significantly related to an increase in collateral formation, regression was significantly related to a decrease in collateral formation (p < 0.00001). Because patients in the intervention group exercised for > 3 hours/week, and patients with regression of coronary artery disease even dedicated 5 to 6 hours to leisure time physical activity per week, these findings question whether an exercise program within the safety tolerance of patients will be able to induce coronary collateralization in the presence of regression of coronary artery disease.

Physical training in patients with stable chronic heart failure: effects on cardiorespiratory fitness and ultrastructural abnormalities of leg muscles

OBJECTIVES

The present study was designed to evaluate the effect of an ambulatory training program on ultrastructural morphology and the oxidative capacity of skeletal muscle and its relation to central and peripheral hemodynamic variables in patients with chronic heart failure.

BACKGROUND

Clinical evidence supports the hypothesis that exercise intolerance in patients with chronic heart failure is not only a consequence of low cardiac output, but is also a result of alterations in oxidative metabolism of skeletal muscle.

METHODS

Twenty-two patients were prospectively randomized either to a training group (mean [+/-SD] ejection fraction 26 +/- 9%, n = 12) participating in an ambulatory training program or to a physically inactive control group (ejection fraction 27 +/- 10%, n = 10). At baseline and after 6 months, patients underwent symptom-limited bicycle exercise testing, and central and peripheral hemodynamic variables were measured. Percutaneous needle biopsy samples of the vastus lateralis muscle were obtained at baseline and after 6 months. The ultrastructure of skeletal muscle was analyzed by ultrastructural morphometry.

RESULTS

After 6 months, patients in the training group achieved an increase in oxygen uptake at the ventilatory threshold of 23% (from 0.86 +/- 0.2 to 1.07 +/- 0.2 liters/min, p < 0.01 vs. control group) and at peak exercise of 31% (from 1.49 +/- 0.4 to 1.95 +/- 0.4 liters/min, p < 0.01 vs. control group). There was no significant change in oxygen uptake at the ventilatory threshold and at peak exercise in the control group. The total volume density of mitochondria and volume density of cytochrome c oxidase-positive mitochondria increased significantly by 19% (from 4.7 +/- 1.5 to 5.6 +/- 1.5 vol%, p < 0.05 vs. control group) and by 41% (from 2.2 +/- 1.0 to 3.1 +/- 1.0 vol%, p < 0.05 vs. control group) after 6 months of regular physical exercise. Cardiac output at rest and at submaximal exercise remained unchanged but increased during maximal symptom-limited exercise from 11.9 +/- 4.0 to 14.1 +/- 3.3 liters/min in the training group (p < 0.05 vs. baseline; p = NS vs. control group). Peak leg oxygen consumption increased significantly by 45% (from 510 +/- 172 to 740 +/- 254 ml/min, p < 0.01 vs. control group). Changes in cytochrome c oxidase-positive mitochondria were significantly related to changes in oxygen uptake at the ventilatory threshold (r = 0.82, p < 0.0001) and at peak exercise (r = 0.87, p < 0.0001).

CONCLUSIONS

Regular physical training increases maximal exercise tolerance and delays anaerobic metabolism during submaximal exercise in patients with stable chronic heart failure. Improved functional capacity is closely linked to an exercise-induced increase in the oxidative capacity of skeletal muscle.

Bradykinin antagonism inhibits the antigrowth effect of converting enzyme inhibition in the dog myocardium after discrete transmural myocardial necrosis

BACKGROUND

Converting enzyme inhibitor (CEI) therapy, but not angiotensin II subtype I receptor blockade, has been shown to attenuate left ventricular remodeling in the dog after transmyocardial direct current (DC) shock. The purpose of this study was to address the importance of preservation of bradykinin to the antiremodeling effect of CEI treatment in this model.

METHODS AND RESULTS

Twenty-four hours after DC shock, adult mongrel dogs were assigned to one of three groups: a control group; a group treated with ramipril 10 mg BID; and a group treated with ramipril 10 mg BID along with a continuous subcutaneous infusion of HOE 140, a bradykinin antagonist. To assess change in left and right ventricular structure, a magnetic resonance imaging (MRI) study was performed 4 weeks after DC shock and compared with a baseline MRI study performed before DC shock. The increase in left ventricular mass (mean +/- SEM) in the control group was similar to that observed in the CEI-HOE 140 group (+0.73 +/- 0.19 versus +0.75 +/- 0.18 g/kg, P = NS), but both were greater than the change in mass in the ramipril group (-0.48 +/- 0.13 g/kg, P = .004 and P = .0005, respectively). No significant change occurred in left ventricular volume or right ventricular structure in any group. Mean arterial pressure was reduced by ramipril compared with the control group (-8 +/- 2 versus +7 +/- 2 mm Hg, P = .03), and this effect was not blunted by the addition of HOE 140 (-7 +/- 3 mm Hg).

CONCLUSIONS

Prevention by ramipril of the early increase in left ventricular mass in the DC shock model appears to be related to the preservation of bradykinin.

Relative effects of alpha 1-adrenoceptor blockade, converting enzyme inhibitor therapy, and angiotensin II subtype 1 receptor blockade on ventricular remodeling in the dog

BACKGROUND

Progressive ventricular remodeling after myocardial damage is associated with a poor prognosis. Optimal prevention of the histopathological processes involved in remodeling requires a more complete understanding of the mechanisms involved in initiating and maintaining these structural changes. Since the sympathetic nervous system and the renin-angiotensin system may be involved in the remodeling process, the structural effects of pharmacological inhibitors have been evaluated in a canine model of localized myocardial injury resulting from transmyocardial DC shock.

METHODS AND RESULTS

The study is comprised of two protocols run in series. In protocol 1, zofenopril (Z), a converting enzyme inhibitor (CEI), prevented the increase in left ventricular mass (LVM) and end-diastolic volume (LVV) observed in the control group (C) at 16 weeks (Z: LVM, 69.8 +/- 3.4 to 65.4 +/- 2.6 g, P = NS; LVV, 45.4 +/- 2.7 to 51.6 +/- 2.7 mL, P = NS; C: LVM, 68.4 +/- 3.2 to 91.4 +/- 2.9 g, P = .0001; LVV, 56.6 +/- 3.0 to 71.9 +/- 2.4 mL, P = .0003). Terazosin, an alpha 1-adrenoceptor antagonist, failed to prevent remodeling at 16 weeks despite continued receptor blockade. In protocol 2, the antiremodeling effect of full-dose CEI therapy with ramipril was confirmed. Low-dose ramipril that exerted no hemodynamic effect failed to prevent remodeling (LVM, 89.7 +/- 4.6 to 105.7 +/- 3.4 g, P = .01; LVV, 61.8 +/- 3.8 to 76.8 +/- 3.3 mL, P = .002). An angiotensin II subtype 1 receptor blocker also failed to prevent the increase in LVM or LVV (LVM, 89.0 +/- 4.6 to 109.7 +/- 5.3 g, P = .0001; LVV, 66.0 +/- 1.9 to 78.4 +/- 3.6 mL, P = .007).

CONCLUSIONS

High-dose CEI therapy can prevent progressive structural changes resulting from localized myocardial damage induced by DC shock. the failure of alpha 1-adrenoceptor blockade and angiotensin II subtype 1 blockade to attenuate remodeling argues against an important direct role for norepinephrine acting through alpha 1-receptors or angiotensin II acting through the type 1 receptor in the remodeling process in this model.