T Cell Exhaustion

T cell responses must be balanced to ensure adequate protection against malignant transformation and an array of pathogens while also limiting damage to healthy cells and preventing autoimmunity. T cell exhaustion serves as a regulatory mechanism to limit the activity and effector function of T cells undergoing chronic antigen stimulation. Exhausted T cells exhibit poor proliferative potential; high inhibitory receptor expression; altered transcriptome, epigenome, and metabolism; and, most importantly, reduced effector function. While exhaustion helps to restrain damage caused by aberrant T cells in settings of autoimmune disease, it also limits the ability of cells to respond against persistent infection and cancer, leading to disease progression. Here we review the process of T cell exhaustion, detailing the key characteristics and drivers as well as highlighting our current understanding of the underlying transcriptional and epigenetic programming. We also discuss how exhaustion can be targeted to enhance T cell functionality in cancer. Expected final online publication date for the Annual Review of Immunology, Volume 42 is April 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

High interindividual variability in LDL-cholesterol reductions after inclisiran administration in a real-world multicenter setting in Germany

BACKGROUND AND AIMS

Low-density lipoprotein cholesterol (LDL-C) is the main therapeutic target in the treatment of hypercholesterolemia. Small interfering RNA (siRNA) inclisiran is a new drug, which targets PCSK9 mRNA in the liver, reducing concentrations of circulating LDL-C. In randomized trials, inclisiran demonstrated a substantial reduction in LDL-C. The German Inclisiran Network (GIN) aims to evaluate LDL-C reductions in a real-world cohort of patients treated with inclisiran in Germany.

METHODS

Patients who received inclisiran in 14 lipid clinics in Germany for elevated LDL-C levels between February 2021 and July 2022 were included in this analysis. We described baseline characteristics, individual LDL-C changes (%) and side effects in 153 patients 3 months (n = 153) and 9 months (n = 79) after inclisiran administration.

RESULTS

Since all patients were referred to specialized lipid clinics, only one-third were on statin therapy due to statin intolerance. The median LDL-C reduction was 35.5% at 3 months and 26.5% at 9 months. In patients previously treated with PCSK9 antibody (PCSK9-mAb), LDL-C reductions were less effective than in PCSK9-mAb-naïve patients (23.6% vs. 41.1% at 3 months). Concomitant statin treatment was associated with more effective LDL-C lowering. There was a high interindividual variability in LDL-C changes from baseline. Altogether, inclisiran was well-tolerated, and side effects were rare (5.9%).

CONCLUSION

In this real-world patient population referred to German lipid clinics for elevated LDL-C levels, inclisiran demonstrated a high interindividual variability in LDL-C reductions. Further research is warranted to elucidate reasons for the interindividual variability in drug efficacy.

Tet2 deletion in CD4+ T cells disrupts Th1 lineage commitment in memory cells and enhances T follicular helper cell recall responses to viral rechallenge

Following viral clearance, antigen-specific CD4+ T cells contract and form a pool of distinct Th1 and Tfh memory cells that possess unique epigenetic programs, allowing them to rapidly recall their specific effector functions upon rechallenge. DNA methylation programing mediated by the methylcytosine dioxygenase Tet2 contributes to balancing Th1 and Tfh cell differentiation during acute viral infection; however, the role of Tet2 in CD4+ T cell memory formation and recall is unclear. Using adoptive transfer models of antigen-specific wild type and Tet2 knockout CD4+ T cells, we find that Tet2 is required for full commitment of CD4+ T cells to the Th1 lineage and that in the absence of Tet2, memory cells preferentially recall a Tfh like phenotype with enhanced expansion upon secondary challenge. These findings demonstrate an important role for Tet2 in enforcing lineage commitment and programing proliferation potential, and highlight the potential of targeting epigenetic programing to enhance adaptive immune responses.

Generation of antigen-specific memory CD4 T cells by heterologous immunization enhances the magnitude of the germinal center response upon influenza infection

Current influenza vaccine strategies have yet to overcome significant obstacles, including rapid antigenic drift of seasonal influenza viruses, in generating efficacious long-term humoral immunity. Due to the necessity of germinal center formation in generating long-lived high affinity antibodies, the germinal center has increasingly become a target for the development of novel or improvement of less-efficacious vaccines. However, there remains a major gap in current influenza research to effectively target T follicular helper cells during vaccination to alter the germinal center reaction. In this study, we used a heterologous infection or immunization priming strategy to seed an antigen-specific memory CD4+ T cell pool prior to influenza infection in mice to evaluate the effect of recalled memory T follicular helper cells in increased help to influenza-specific primary B cells and enhanced generation of neutralizing antibodies. We found that heterologous priming with intranasal infection with acute lymphocytic choriomeningitis virus (LCMV) or intramuscular immunization with adjuvanted recombinant LCMV glycoprotein induced increased antigen-specific effector CD4+ T and B cellular responses following infection with a recombinant influenza strain that expresses LCMV glycoprotein. Heterologously primed mice had increased expansion of secondary Th1 and Tfh cell subsets, including increased CD4+ TRM cells in the lung. However, the early enhancement of the germinal center cellular response following influenza infection did not impact influenza-specific antibody generation or B cell repertoires compared to primary influenza infection. Overall, our study suggests that while heterologous infection/immunization priming of CD4+ T cells is able to enhance the early germinal center reaction, further studies to understand how to target the germinal center and CD4+ T cells specifically to increase long-lived antiviral humoral immunity are needed.

Tet2 coordinates with Foxo1 and Runx1 to balance T follicular helper cell and T helper 1 cell differentiation

In response to various types of infection, naïve CD4+ T cells differentiate into diverse helper T cell subsets; however, the epigenetic programs that regulate differentiation in response to viral infection remain poorly understood. Demethylation of CpG dinucleotides by Tet methylcytosine dioxygenases is a key component of epigenetic programing that promotes specific gene expression, cellular differentiation, and function. We report that following viral infection, Tet2-deficient CD4+ T cells preferentially differentiate into highly functional germinal center T follicular helper (TFH) cells that provide enhanced help for B cells. Using genome-wide DNA methylation and transcription factor binding analyses, we find that Tet2 coordinates with multiple transcription factors, including Foxo1 and Runx1, to mediate the demethylation and expression of target genes, including genes encoding repressors of TFH differentiation. Our findings establish Tet2 as an important regulator of TFH cell differentiation and reveal pathways that could be targeted to enhance immune responses against infectious disease.

Tet2-mediated programing balances T follicular helper cell and T helper 1 cell differentiation

The differentiation of CD4+ T cell subsets in response to infection has been studied extensively, however the epigenetic programs that regulate these processes remain poorly understood. Active demethylation by tet methylcytosine dioxygenases of CpG dinucleotides within DNA is a key component of epigenetic programing that promotes lineage specific gene expression and contributes to cellular differentiation and function. Here we report that Tet2 acts to restrict the differentiation of T follicular helper (Tfh) cells in CD4+ T cells responding to viral infection. Using an adoptive transfer model of virus-specific CD4+ cells we found that Tet2-deficient CD4+ T cells skew away from the Th1 lineage and instead preferentially differentiate into highly functional germinal center (GC) Tfh cells that provide enhanced help for B cell responses. We found that the impact of Tet2-mediated programing on CD4+ T cell differentiation is cell intrinsic and the shift in lineage differentiation occurs as early as 2 days post infection. Using genome-wide expression, DNA methylation and transcription factor binding analyses, we found that Tet2 coordinates with multiple transcription factors to mediate the demethylation and expression of their target genes following activation. Our findings establish Tet2 as an important regulator of Tfh cell differentiation and reveal pathways that could be targeted to enhance GC responses against infectious disease.

Supported by grants from NIH (R01 AI137238 to J.S.H., T32 AI055434 to L.M.S., and T32 AI138945 to A.B.

Prevalence and time course of arrhythmia-induced cardiomyopathy in patients with newly diagnosed heart failure and concomitant tachyarrhythmia – the TACHY-HF pilot trial

Background

Arrhythmias may often be a result of heart failure, but they can also cause left-ventricular systolic dysfunction (LVSD), thereby presenting as arrhythmia-induced cardiomyopathy (AIC). AIC-diagnosis is established retrospectively when LVSD normalizes or improves significantly over time following rhythm restoration. However, the prevalence and most importantly the time course of this relevant disease remain unclear and hence merit investigation to enable the correct diagnosis.

Purpose

Therefore, our aim was to evaluate a) the occurrence of AIC in this clinical relevant cohort of patients with newly diagnosed and otherwise unexplainable LVSD and concomitant tachycardia and b) the time needed to fulfill the diagnostic criteria of AIC in order to facilitate a diagnostic algorithm.

Method

We prospectively screened patients hospitalized for newly diagnosed and otherwise unexplainable LVSD (i.e. left ventricular ejection fraction (LVEF) <50%) and coexisting tachyarrhythmia (atrial fibrillation/flutter + heart rate (HR) >100/min) in 3 cardiological centers. Coronary angiography and cardiac magnetic resonance imaging were performed to exclude other causes for LVSD. Patients underwent a rhythm control strategy in accordance to the local clinical pathways. LVEF was assessed by echocardiography at presentation and at follow-up (FU) visits after 2, 4, and 6 months. Patients who lost sinus rhythm (SR) during FU were excluded. Patients with any increase of ≥15% in absolute EF or an EF ≥50% with an improvement of ≥10% after 6 months of FU were assigned to the AIC-group, which is a common definition of AIC. All others were assigned to an idiopathic DCM-group as final comparator.

Results

68 patients were eligible, 18 of them were excluded: 1 lost to follow-up, 1 PCI, 2 COVID-19, 1 diagnosed cancer, 1 withdraw consent and 12 lost SR. Thus, our sample consists of a total of 50 patients. At presentation, mean±SD HR was 121±17/min. After rhythm therapy, HR normalized (67±10/min) and LVEF increased in both groups, see fig. 1. Surprisingly, only 9 patients did not fulfill the AIC-criteria in this specific collective resulting in a prevalence of 82% (95%-CI: 68% – 92%). This high prevalence of AIC underlines the importance of the disease. 2 and 4 months after rhythm intervention, 58% and 73% of patients fulfilled AIC-criteria (fig. 2). The sensitivity for detection of AIC by echocardiographic LVEF-measurement at months 2 and 4 of FU was 65% and 86% with a specificity of 100%, emphasizing that a FU of 6 months is necessary to certainly distinguish between AIC and idiopathic DCM.

Conclusion

The prevalence of AIC in patients with newly diagnosed and otherwise unexplainable LVSD with concomitant tachycardia is 82%. Analysis of the time course of AIC clearly suggests that the final diagnosis cannot be established before 6 months after successful rhythm restoration. These results may help to improve diagnosis of AIC in daily clinical practice.

Funding Acknowledgement

Type of funding sources: None.

Protein Immunization Induces Memory CD4+ T Cells That Lack Th Lineage Commitment

Acute viral infection generates lineage-committed Th1 and T follicular helper (Tfh) memory cells that recall their lineage-specific functions following secondary challenge with virus. However, the lineage commitment of effector and memory Th cells in vivo following protein vaccination is poorly understood. In this study, we analyzed effector and memory CD4⁺ T cell differentiation in mice (Mus musculus) following adjuvanted glycoprotein immunization compared with acute lymphocytic choriomeningitis virus infection. Glycoprotein immunization induced CXCR5^- non-Tfh effector and memory CD4⁺ T cells that surprisingly had not undergone polarization toward any particular Th cell lineage but had undergone memory differentiation. However, upon challenge with virus, these Th lineage-nonpolarized memory CD4⁺ T cells were able to generate Th1 secondary effector cells, demonstrating their lineage plasticity. In addition, Tfh and memory Tfh cells were generated in response to protein immunization, and these cells differed from infection-induced Tfh cells by their lack of the transcription factor Tbet. Rechallenge experiments demonstrated that viral infection, but not protein immunization, during either the primary or secondary immune response, restricts the recall of Bcl6 expression and the generation of germinal center Tfh cells. Together, these data demonstrate that protein immunization generates a combination of nonpolarized memory cells that are highly plastic and memory Tfh cells that can undergo further Th1-like modulation during a secondary response to viral infection.

Protein immunization induces T follicular helper memory cells and nonpolarized T helper (Tnp) memory cells

Acute viral infection generates lineage-committed T helper 1 (Th1) and T follicular helper (Tfh) memory cells that recall their lineage-specific functions following secondary challenge with virus. However, the lineage commitment of effector and memory T helper cells in vivo following protein vaccination is poorly understood. In this study, we analyzed effector and memory CD4+ T cell differentiation following adjuvanted glycoprotein immunization compared to acute lymphocytic choriomeningitis virus (LCMV) infection. Glycoprotein immunization-induced CXCR5-non-Tfh effector and memory CD4+ T cells that surprisingly had not undergone polarization toward any particular T helper cell lineage but had undergone memory differentiation. However, upon challenge with virus, these T helper lineage-nonpolarized memory CD4+ T cells were able to generate Th1 secondary effector cells, demonstrating their lineage plasticity. In addition, Tfh and memory Tfh cells were generated in response to protein immunization, and these cells differed from infection-induced Tfh cells by their lack of the transcription factor Tbet. Rechallenge experiments demonstrated that viral infection, but not protein immunization, during either the primary or secondary immune response, restricts the recall of Bcl6 expression and the generation of germinal center Tfh cells. Together, these data demonstrate that protein immunization generates a combination of nonpolarized memory cells that are highly plastic and memory Tfh cells that can undergo further Th1-like modulation during a secondary response to viral infection.

[Current treatment of endocarditis : Innovations and controversies]

Despite many novel diagnostic strategies and advances in treatment, infective endocarditis (IE) remains a severe disease. The epidemiology of IE has shifted and staphylococci have replaced streptococci as the most common cause and nosocomially acquired infections, invasive procedures, indwelling cardiac devices and acquired infections due to intravenous drug abuse are more frequent. The incidence of IE has steadily increased in recent years and the patients affected are older and have more comorbidities. The modern treatment of IE is interdisciplinary. The pharmacotherapy of IE depends on the pathogen and its sensitivity. The presence of a bioprosthetic valve and implantable cardiac devices plays a significant role in selection of antibiotics and duration of treatment. This article provides an update and overview of the current clinical practice in diagnostics and pharmacotherapy of IE in adults with a special focus on partial oral therapy and the role of aminoglycosides.

Tissue-specific requirements for IL-10 in maintaining homeostasis in response to chronic virus infection

Herpesviruses have co-evolved with their hosts for million of years, establishing an intimate balancing act of lifelong infection with minimal damage to the host. Interleukin (IL)-10 is a major inhibitory cytokine that has been usurped by many herpesviruses to facilitate infection. Here we tested the consequence of IL-10 deficiency on the outcome of murine gammaherpesvirus 68 (γHV68) infection, a small animal model of γHV pathogenesis. While IL-10 deficiency had minimal impact on the control of virus infection, IL-10 deficient mice showed hyper-activation of the immune response with increased levels of T cell activation, effector T cells and prolonged neutrophilia in the infected lung. IL-10 further had a non-redundant role in limiting intestinal inflammation with chronically infected mice showing a prolonged failure to thrive following infection, associated with enhanced colonic Th1 responses. CD4 T cells were a prominent source of IL10 during acute and chronic infection, with IL10+ interferon-gamma+ FoxP3- type 1 regulatory CD4 T cells as the major early source of IL10. High-dimensional mass cytometric analysis of IL10 expressing cells, and IL10 responsive cells, identified a constellation of phenotypes that correlate with robust IL10 expression, and further identified direct and indirect targets of IL10. In total, these data demonstrate the context dependent role of IL10 in constraining the antiviral host response and identify IL10-dependent and –independent regulatory pathways in regulating chronic herpesvirus infection.

This research was funded by grants from the American Heart Association, Crohn’s and Colitis Foundation of America and the UC Department of Anesthesiology (ETC).

Failure to achieve recommended LDL cholesterol levels by suboptimal statin therapy relates to elevated cardiac event rates

OBJECTIVES

The majority of patients with myocardial infarction (MI) and hypercholesterolaemia does not achieve guideline recommended low-density lipoprotein cholesterol (LDL) levels. Suboptimal dosages of statins explain this dilemma in most patients.

DESIGN AND SETTING

We evaluated the relationship between statin treatment quality (optimal: LDL<115 mg/dl, suboptimal: LDL>/=115 mg/dl, no statin therapy despite hypercholesterolaemia) and the subsequent incidence of coronary events (coronary death, nonfatal MI, bypass surgery) over a 30 months follow-up in a large cohort of post MI patients with hypercholesterolaemia (n=2045). Analysis was performed in a nested case-control manner comparing 173 cases with a coronary event and 346 matched controls.

RESULTS

Patients who developed a coronary event were treated optimally in 11.0%, suboptimally in 43.4% (p<0.05 vs. optimal treatment) and were untreated in 45.7% (p<0.001 vs. optimal treatment). Respective numbers in event-free patients were 21.4%, 47.7%, and 30.9%. After adjustment for most potential confounders, including all cardiovascular risk factors and medication, the relative risk of future non-fatal MI and coronary death associated with a suboptimal statin treatment was 2.02 (95% CI 1.04 to 4.18) compared to optimal statin treatment. Moreover, the statin equivalent dose in optimally treated individuals was significantly higher than in suboptimally treated individuals (0.85+/-0.03 vs. 0.78+/-0.02, p<0.05).

CONCLUSION

In this community-based study, a lipid lowering therapy with statins into the recommended target range of LDL levels may be associated with decreased cardiovascular risk compared to a statin therapy without titrating the LDL level below 115 mg/dl. Thus, the quality of statin treatment was identified as an independent predictor of coronary events in post MI patients.

[Epidemiology of left ventricular systolic dysfunction in the general population of Germany: results of an echocardiographic study of a large population-based sample]

The prevalence of left ventricular systolic dysfunction (LVSD) in the general population is poorly defined. Specifically, the number of asymptomatic individuals with LVSD and, thus, the most appropriate strategy to identify and treat such subjects is still unknown. Therefore, the aim of this study was to document LV dysfunction in a middle-aged (25 to 75 years, mean 51.8+/-13.8) population - based sample in Germany (MONICA Augsburg, n=1678; echocardiography technically adequate n=1418) by M-mode and 2D-echocardiography and to analyze the importance of predisposing contributors. The overall prevalence of an ejection fraction (EF) less than 48% (mean minus 2 SD=LVSD) was 2.3% (n=33), with a slightly higher rate in men than in women (2.8% vs 1.9%, n.s.). LVSD rate increased with age: from 1.5% in individuals younger than 40 years to 4.0% among those older than 60 years of age (p<0.05). Of 33 participants with reduced left ventricular systolic function, 20 presented with at least one cardiovascular disease. The most frequent diagnoses were arterial hypertension, obesity and coronary heart disease. Only 13 subjects (0.9%) of the study population were asymptomatic without a history of cardiovascular disease. Furthermore, only 6 subjects (0.4%, 4 male) in this population presented with a moderate impairment of LV function (EF of 30 to 40%) and only 1 subject (0.07%, male) had severe LVSD (EF less than 30%). Almost all subjects with an EF less than 40% (6 of 7 individuals) had a known history of cardiovascular disease. In conclusion, LVSD is a relatively common finding in the general population. However, severe LVSD is rare in subjects without any concomitant cardiovascular disease. Thus, echocardiographic screening cannot be recommended in the unselected, middle-aged population to identify such patients.

Prevalence of left ventricular diastolic dysfunction in the community. Results from a Doppler echocardiographic-based survey of a population sample

AIMS

The prevalence of left ventricular diastolic abnormalities in the general population is largely unclear. Thus, the aim of this study was, firstly, to identify abnormal diastolic function by echocardiography in an age-stratified population-based European sample (MONICA Augsburg, n=1274, 25 to 75 years, mean 51+/-14) and, secondly, to analyse clinical and anthropometric parameters associated with diastolic abnormalities.

METHODS AND RESULTS

The overall prevalence of diastolic abnormalities, as defined by the European Study Group on Diastolic Heart Failure (i.e. age dependent isovolumic relaxation time (92-105 ms) and early (E-wave) and late (A-wave) left ventricular filling (E/A-ratio, 1-0.5)) was 11.1%. When only subjects treated with diuretics or with left atrial enlargement were considered (suggesting diastolic dysfunction) the prevalence was 3.1%. The prevalence of diastolic abnormalities varied according to age: from 2.8% in individuals aged 25-35 years to 15.8% among those older than 65 years (P<0.01). Significantly higher rates of diastolic abnormalities were observed in men as compared to women (13.8% vs 8.6%, P<0.01). Independent predictors of diastolic abnormalities were arterial hypertension, evidence of left ventricular (LV) hypertrophy, and coronary artery disease. Interestingly, in the absence of these predisposing conditions, diastolic abnormalities (4.3%) or diastolic dysfunction (1.1%) were rare, even in subjects older than 50 years of age (4.6%) and (1.2%), respectively. In addition to these factors, diastolic dysfunction was related to high body mass index, high body fat mass, and diabetes mellitus.

CONCLUSION

The prevalences of diastolic abnormalities and diastolic dysfunction are higher than that of systolic dysfunction and are increased (despite age-dependent diagnostic criteria) in the elderly. However, in the absence of risk factors for diastolic abnormalities or diastolic dysfunction, namely LV hypertrophy, arterial hypertension, coronary artery disease, obesity and diabetes the condition is rare even in elderly subjects. These data allow speculation on whether diastolic heart failure may be prevented by improved implementation of measures directed against predisposing conditions.

[Inpatient rehabilitation improves implementation of therapeutic guidelines for secondary prevention in patients with coronary heart disease]

In Germany, measures for secondary prevention in patients with coronary artery disease are poorly utilized. We therefore investigated whether a cardiac in-hospital rehabilitation and education program may enhance the implementation of respective guidelines in patients with severe coronary artery disease (CAD). Specifically, we developed a case-control design in siblings with severe CAD in order to achieve optimal matching for patients with or without participation in the rehabilitation program. By the screening of more than 200,000 patient charts in 15 cardiac rehabilitation clinics, we identified 1500 families in which at least two siblings suffered from severe coronary artery disease. In 268 such sibling pairs, siblings were discordant with respect to participation in a 3-4 week cardiac in-hospital rehabilitation program. The coronary risk profile was studied, first, retrospectively at the time of hospitalization for acute MI or revascularization procedures and, secondly, prospectively at the time of follow-up (on average 5.2 years later). At the time of the acute cardiac event, both groups showed an equal risk factor distribution suggesting appropriate matching. However, at follow-up the number of individuals taking antihypertensive medication and displaying effective antihypertensive treatment (< or = 140/90 mmHg) was significantly higher in the rehabilitation group (92.2 vs. 82.1%, p < 0.01; 59.7 vs. 37.2%). Accordingly, rehabilitation siblings presented with significantly lower systolic (137 +/- 1 vs. 145 +/- 1 mmHg; p < 0.01) and diastolic blood pressure (82 +/- 1 vs. 85 +/- 1 mmHg; p < 0.01). The utilization of CSE inhibitors was also significantly higher in siblings participating in the rehabilitation program (57.5 vs. 43.1%; p < 0.01), leading to significantly lower blood lipid levels in these siblings (total cholesterol 225 +/- 3 vs. 236 +/- 3 mg/dL, p < 0.01; LDL cholesterol 148 +/- 3 vs. 158 +/- 3 mg/dL, p < 0.01). Moreover, participation in the cardiac rehabilitation stimulated markedly more smokers to quit (80.8 vs. 57.6%, p < 0.01). Additionally, there was a strong temporal trend from 1997 until 2000 towards improved control of arterial hypertension in rehabilitation siblings. In parallel, the utilization of CSE inhibitors increased over time and LDL cholesterol decreased. These favorable temporal trends were also observed in siblings not participating in the rehabilitation program, however, to a lesser extent. Taken together, in the last four years, the implementation of secondary preventive strategies in patients with cardiac disease improved. Siblings who participated in a rehabilitation program displayed a better control of cardiovascular risk factors as compared to those not participating in such a program. Thus, an in-hospital cardiac rehabilitation program may successfully encourage the implementation of measures for secondary prevention and enhance the treatment of coronary risk factors.

Long-term effects of in-hospital cardiac rehabilitation on the cardiac risk profile. A case-control study in pairs of siblings with myocardial infarction

AIMS

In the general population, measures for secondary prevention of myocardial infarction are poorly utilized. Our aim was therefore to analyse whether post-myocardial infarction in-hospital rehabilitation and education programmes improve the subsequent utilization of preventive strategies.

METHODS AND RESULTS

We screened 93 500 patient charts in cardiac rehabilitation clinics to identify a myocardial infarction patient with a sibling, who likewise had a myocardial infarction prior to the age of 60 years but was discordant with respect to the participation in cardiac in-hospital rehabilitation. In 92 such sibling pairs the coronary risk profile was studied by standardized questionnaire, biochemical measurements and physical examination. At the time of the acute myocardial infarction, both groups showed an equal risk factor distribution. However, at follow-up (on average 5.5 years after myocardial infarction), rehabilitation-siblings presented with significantly lower systolic (137+/-2 vs 150+/-3 mmHg, P<0.01) and diastolic blood pressure (82+/-1 vs 89+/-1 mmHg, P<0.01). Antihypertensive drug therapy resulted more often in effective (<or=140/90 mmHg) control of blood pressure (58% vs 29%, P<0.01). Blood lipid levels and smoking prevalence tended to be lower in rehabilitation-siblings. Significantly fewer rehabilitation-siblings presented with two or more modifiable risk factors (OR 0.36 (CI 0.17-0.76); P<0.01). There was a strong tendency towards fewer recurrent cardiac events (re-myocardial infarction, coronary angioplasty, coronary artery bypass grafting) during follow-up in rehabilitation-siblings (OR 0.57 (CI 0.31-1.04); P=0.07).

CONCLUSION

An in-hospital programme for cardiac rehabilitation may successfully encourage therapy to modify risk factors and thus enhance the long-term implementation of secondary prevention.