The Effect of Heat Exposure on Myocardial Blood Flow and Cardiovascular Function.

BACKGROUND: Heat extremes are associated with greater risk for cardiovascular death. The pathophysiologic mechanisms mediating this association are unknown. OBJECTIVE: To quantify the myocardial blood flow (MBF) requirements of heat exposure. DESIGN: Experimental study. (ClinicalTrials.gov: NCT04549974). SETTING: Laboratory-based. PARTICIPANTS: 61 participants, comprising 20 healthy young adults (mean age, 28 years), 21 healthy older adults (mean age, 67 years), and 20 older adults with coronary artery disease (CAD) (mean age, 70 years). INTERVENTION: Participants were heated until their core temperature increased 1.5 °C; MBF was measured before heat exposure and at every increase of 0.5 °C in core temperature. MEASUREMENTS: The primary outcome was MBF measured by positron emission tomography-computed tomography. Secondary outcomes included heart rate, blood pressure, and body weight change. RESULTS: At a core temperature increase of 1.5 °C, MBF increased in healthy young adults (change, 0.8 mL/min/g [95% CI, 0.5 to 1.0 mL/min/g]), healthy older adults (change, 0.7 mL/min/g [CI, 0.5 to 0.9 mL/min/g]), and older adults with CAD (change, 0.6 mL/min/g [CI, 0.3 to 0.8 mL/min/g]). This represented a 2.08-fold (CI, 1.75- to 2.41-fold), 1.79-fold (CI, 1.59- to 1.98-fold), and 1.64-fold (CI, 1.41- to 1.87-fold) change, respectively, from preexposure values. Imaging evidence of asymptomatic heat-induced myocardial ischemia was seen in 7 adults with CAD (35%) in post hoc analyses. LIMITATIONS: In this laboratory-based study, heating was limited to about 100 minutes and participants were restricted in movement and fluid intake. Participants refrained from strenuous exercise and smoking; stopped alcohol and caffeine intake; and withheld ß-blockers, calcium-channel blockers, and nitroglycerin before heating. CONCLUSION: Heat exposure that increases core temperature by 1.5 °C nearly doubles MBF. Changes in MBF did not differ by age or presence of CAD, but some older adults with CAD may experience asymptomatic myocardial ischemia. PRIMARY FUNDING SOURCE: Canadian Institutes of Health Research.

Beta-Blocker Type Effect on Substrate Oxidation during HIIE in Heart Failure Patients: Pilot Data / Efeito do Tipo Betabloqueador na Oxidação de Substratos durante HIIE em Pacientes com Insuficiência Cardíaca: Dados Piloto

Abstract The effect of third and second-generation type of beta-blocker on substrate oxidation especially during high-intensity exercises are scarce. The objective of the study is to explore differences of beta-blocker regimens (vasodilating vs. non-vasodilating beta-blockers) for substrate oxidation during in high-intensity intermittent exercise (HIIE) in chronic heart failure and reduced ejection fraction (HFrEF). Eighteen CHF males (58.8 ± 9 years), 8 under use of β1 specific beta-blockers+alfa 1-blocker and 10 using β1 non-specific beta-blockers, were randomly assigned to 4 different HIIE, in a cross-over design. The 4 protocols were: 30 seconds (A and B) or 90 seconds (C and D) at 100% peak power output, with passive (A and C) or active recovery (50% of PPO; B and D). Energy expenditure (EE; kcal/min), quantitative carbohydrate (CHO) and lipid oxidation (g/min) and qualitative (%) contribution were calculated. Two-way ANOVA and Bonferroni post-hoc test were used (p-value ≤ 0.05) to compare CHO and lipid oxidation at rest and at 10min. Total exercise time or EE did not show differences for beta-blocker use. The type of beta-blocker use showed impact in CHO (%) and lipid (g/min and %) for rest and 10 min, but absolute contribution of CHO (g/min) was different just at 10min (Interaction p = 0.029). Higher CHO oxidation was found in vasodilating beta-blockers when comparing to non-vasodilating. According to our pilot data, there is an effect of beta-blocker type on substrate oxidation during HIIE, but no influence on EE or exercise total time in HFrEF patients.

Resumo Os dados sobre efeito do tipo de betabloqueador de terceira e segunda geração na oxidação do substrato, especialmente durante exercícios de alta intensidade, são escassos. O objetivo do estudo é explorar as diferenças de tratamentos com betabloqueadores (betabloqueadores vasodilatadores vs. não-vasodilatadores) na oxidação de substratos durante exercícios intermitentes de alta intensidade (HIIE) na insuficiência cardíaca crônica e fração de ejeção do ventrículo esquerdo reduzida (ICFEr). Dezoito pacientes do sexo masculino com ICC (58,8 ± 9 anos), 8 em uso de betabloqueadores β1 específicos + bloqueador α-1 e 10 utilizando betabloqueadores β1 não-específicos, foram aleatoriamente designados para 4 diferentes HIIE, em um desenho cruzado. Os 4 protocolos foram: 30 segundos (A e B) ou 90 segundos (C e D) a 100% da potência de pico de saída (PPO), com recuperação passiva (A e C) ou ativa (50% de PPO; B e D). O gasto energético (GE; kcal/min), a ingestão de carboidratos quantitativos (CHO) e oxidação lipídica (g/min) e qualitativa (%) foram calculados. Anova de dois fatores e teste post-hoc de Bonferroni foram usados (p-valor ≤ 0,05) para comparar a oxidação de CHO e lipídios em repouso e aos 10 minutos. O tempo total de exercício ou GE não mostraram diferenças de acordo com o uso de betabloqueadores. O tipo de betabloqueador mostrou impacto em CHO (%) e lípides (g/min e %) para repouso e aos 10 min, mas a contribuição absoluta de CHO (g/min) foi diferente apenas aos 10 minutos (Interação p = 0,029). Foram encontradas maiores oxidações de CHO com betabloqueadores vasodilatadores quando comparados com os não-vasodilatadores. De acordo com nossos dados piloto, há um efeito do tipo do betabloqueador na oxidação do substrato durante o HIIE, mas nenhuma influência no GE ou no tempo total de exercício nos pacientes com ICFEr.

Evaluation of a Web-Based Tailored Nursing Intervention (TAVIE en m@rche) Aimed at Increasing Walking After an Acute Coronary Syndrome: A Multicenter Randomized Controlled Trial Protocol.

BACKGROUND: Despite the health benefits of increasing physical activity in the secondary prevention of acute coronary syndrome (ACS), up to 60% of ACS patients are insufficiently active. Evidence supporting the effect of Web-based interventions on increasing physical activity outcomes in ACS patients is growing. However, randomized controlled trials (RCTs) using Web-based technologies that measured objective physical activity outcomes are sparse. OBJECTIVE: Our aim is to evaluate in insufficiently active ACS patients, the effect of a fully automated, Web-based tailored nursing intervention (TAVIE en m@rche) on increasing steps per day. METHODS: A parallel two-group multicenter RCT (target N=148) is being conducted in four major teaching hospitals in Montréal, Canada. An experimental group receiving the 4-week TAVIE en m@rche intervention plus a brief "booster" at 8 weeks, is compared with the control group receiving hyperlinks to publicly available websites. TAVIE en m@rche is based on the Strengths-Based Nursing Care orientation to nursing practice and the Self-Determination Theory of human motivation. The intervention is centered on videos of a nurse who delivers the content tailored to baseline levels of self-reported autonomous motivation, perceived competence, and walking behavior. Participants are recruited in hospital and are eligible if they report access to a computer and report less than recommended physical activity levels 6 months before hospitalization. Most outcome data are collected online at baseline, and 5 and 12 weeks postrandomization. The primary outcome is change in accelerometer-measured steps per day between randomization and 12 weeks. The secondary outcomes include change in steps per day between randomization and 5 weeks, and change in self-reported energy expenditure for walking and moderate to vigorous physical activity between randomization, and 5 and 12 weeks. Theoretical outcomes are the mediating role of self-reported perceived autonomy support, autonomous and controlled motivations, perceived competence, and barrier self-efficacy on steps per day. Clinical outcomes are quality of life, smoking, medication adherence, secondary prevention program attendance, health care utilization, and angina frequency. The potential moderating role of sex will also be explored. Analysis of covariance models will be used with covariates such as sex, age, fatigue, and depression symptoms. Allocation sequence is concealed, and blinding will be implemented during data analysis. RESULTS: Recruitment started March 30, 2016. Data analysis is planned for November 2017. CONCLUSIONS: Finding alternative interventions aimed at increasing the adoption of health behavior changes such as physical activity in the secondary prevention of ACS is clearly needed. Our RCT is expected to help support the potential efficacy of a fully automated, Web-based tailored nursing intervention on the objective outcome of steps per day in an ACS population. If this RCT is successful, and after its implementation as part of usual care, TAVIE en m@rche could help improve the health of ACS patients at large. TRIAL REGISTRATION: ClinicalTrials.gov NCT02617641; https://clinicaltrials.gov/ct2/show/NCT02617641 (Archived by WebCite at http://www.webcitation.org/6pNNGndRa).

Provocative issues in heart disease prevention.

In this article, new areas of cardiovascular (CV) prevention and rehabilitation research are discussed: high-intensity interval training (HIIT) and new concepts in nutrition. HIIT consists of brief periods of high-intensity exercise interspersed by periods of low-intensity exercise or rest. The optimal mode according our work (15-second exercise intervals at peak power with passive recovery intervals of the same duration) is associated with longer total exercise time, similar time spent near peak oxygen uptake (VO2 peak) VO2 peak, and lesser perceived exertion relative to other protocols that use longer intervals and active recovery periods. Evidence also suggests that compared with moderate-intensity continuous exercise training, HIIT has superior effects on cardiorespiratory function and on the attenuation of multiple cardiac and peripheral abnormalities. With respect to nutrition, a growing body of evidence suggests that the gut microbiota is influenced by lifestyle choices and might play a pivotal role in modulating CV disease development. For example, recent evidence linking processed (but not unprocessed) meats to increased CV risk pointed to the gut microbial metabolite trimethylamine N-oxide as a potential culprit. In addition, altered gut microbiota could also mediate the proinflammatory and cardiometabolic abnormalities associated with excess added free sugar consumption, and in particular high-fructose corn syrup. Substantially more research is required, however, to fully understand how and which alterations in gut flora can prevent or lead to CV disease and other chronic illnesses. We conclude with thoughts about the appropriate role for HIIT in CV training and future research in the role of gut flora-directed interventions in CV prevention.

Exercise and longevity.

Aging is a natural and complex physiological process influenced by many factors, some of which are modifiable. As the number of older individuals continues to increase, it is important to develop interventions that can be easily implemented and contribute to "successful aging". In addition to a healthy diet and psychosocial well-being, the benefits of regular exercise on mortality, and the prevention and control of chronic disease affecting both life expectancy and quality of life are well established. We summarize the benefits of regular exercise on longevity, present the current knowledge regarding potential mechanisms, and outline the main recommendations. Exercise can partially reverse the effects of the aging process on physiological functions and preserve functional reserve in the elderly. Numerous studies have shown that maintaining a minimum quantity and quality of exercise decreases the risk of death, prevents the development of certain cancers, lowers the risk of osteoporosis and increases longevity. Training programs should include exercises aimed at improving cardiorespiratory fitness and muscle function, as well as flexibility and balance. Though the benefits of physical activity appear to be directly linked to the notion of training volume and intensity, further research is required in the elderly, in order to develop more precise recommendations, bearing in mind that the main aim is to foster long-term adherence to physical activity in this growing population.

Heart rate recovery after exercise and long-term prognosis in patients with coronary artery disease.

BACKGROUND: The long-term prognostic value of heart rate recovery (HRR) has been incompletely documented in patients with coronary artery disease (CAD). We sought to confirm the prognostic value of HRR in a large cohort with stable CAD. METHODS: From the Coronary Artery Surgery Study registry, a database of 24,958 patients with CAD who underwent cardiac catheterization between 1974 and 1979, we identified 4097 patients with baseline exercise stress testing data. HRR was measured at 3 minutes post exercise during a passive recovery. Clinical outcomes were evaluated according to HRR in both threshold and continuous models. RESULTS: Median long-term follow-up was 14.7 years (interquartile range, 9.8-16.2). HRR < 46 beats per minute (Bpm) most appropriately differentiated nonsurvivors from survivors (area under receiver operating characteristic curve = 0.613) and was associated with an increased risk of all-cause death (adjusted hazard ratio = 1.15; P = 0.011). Increasing HRR was associated with a lower risk of all-cause (adjusted hazard ratio = 0.94 per 10 Bpm; 95% confidence interval, 0.91-0.97; P = 0.0005) and cardiovascular (CV) mortality (adjusted hazard ratio = 0.94 per 10 Bpm; 95% confidence interval, 0.90-0.98; P = 0.003). CONCLUSIONS: HRR at 3 minutes independently predicts long-term all-cause and CV mortality in patients with stable CAD. Measurement of HRR at 3 minutes during passive recovery can be used as a complementary tool to identify patients with a higher total and CV risk.

Randomized controlled trial of tailored nursing interventions to improve cardiac rehabilitation enrollment.

BACKGROUND: Short hospital stays for patients with acute coronary syndromes (ACSs) reduce the opportunity for risk factor intervention during admission. After discharge, cardiac rehabilitation can decrease the recurrence of coronary events by up to 25%. However, it remains underused. OBJECTIVES: The aim of this study was to determine whether a nursing intervention focused on individual ACS patients' perceptions of their disease and treatment would increase rehabilitation enrollment after discharge. METHOD: A total of 242 ACS patients admitted to a specialized tertiary cardiac center were randomized to either the intervention or usual care (n = 121 in both groups). The intervention included one nurse-patient meeting before discharge with 2 additional contacts over the 10 days after discharge (mean duration = 40 minutes per contact). The primary outcome was enrollment in a free rehabilitation program offered to all participants 6 weeks after discharge. Secondary outcomes included illness perceptions; family support; anxiety level; medication adherence; and cardiac risk factors including lack of exercise, smoking, body mass index, and diet. RESULTS: The sample was composed of a majority of male, married workers who experienced a myocardial infarction or unstable angina without severe complications. The mean hospital stay in both groups was 3.6 days. There was a significantly higher rate of rehabilitation enrollment in the intervention group (45%) than in the control group (24%; p = .001). For the secondary outcomes, only the personal control dimension of illness perceptions was improved significantly with the intervention. DISCUSSION: Progressive, individualized interventions by nurses resulted in greater rehabilitation enrollment, thereby potentially improving long-term outcome.

A pilot randomized trial of a smoking cessation nursing intervention in cardiac patients after hospital discharge.

BACKGROUND: One fifth of Canadians are smokers despite the availability of community-based smoking cessation programs. It was hypothesized that offering a post-discharge smoking cessation program to cardiac patients would decrease smoking rates at six months. METHOD: This pilot randomized study explored the feasibility, acceptability and preliminary efficacy of a smoking cessation intervention delivered by a smoking cessation nurse specialist (SCNS) to cardiac patients after hospital discharge. SAMPLE: Participants (N=40) were randomized to either a postdischarge telephone intervention delivered weekly for the first month and then monthly until the third month (experimental group [EG]), or referral to usual community care (control group [CG]). FINDINGS: The researchers confirmed the feasibility of recruitment and acceptability of the intervention, but dfficulty with follow-up. The intention-to-treat analysis showed similar smoking cessation rates in both groups at six months (25% EG versus 30% CG; p = 0.72). CONCLUSION: An intensifed follow-up protocol, or a more intensive, comprehensive and multidisciplinary intervention might be required, given the characteristics of the smokers.

[A pre assessment for nursing intervention to support tobacco cessation in patients hospitalized for cardiac problems: a pilot study (So-Live)]. / Evaluation préliminaire d'une intervention infirmière de soutien a la cessation tabagique chez des patients hospitalisés pour un problème cardiaque: etude pilote (So-Live).

OBJECTIVE: The aim of this study was to evaluate the effect of a smoking cessation intervention provided after discharge from a specialized cardiac hospital. DESIGN: A randomized pilot study (N = 40); after discharge, the experimental group (EG) received 6 phone calls from a nurse specialized in tobacco cessation counselling. RESULTS: Patients in the EG showed improved scores on two aspects of illness representations (perceive their illness as chronic and reported less negative emotional representations). No significant difference in smoking cessation was observed at 6 months (p = 0.72). CONCLUSION: The non-significant difference may be explained in part by the smoking characteristics within this sample exemplifying the more nicotine dependent "hard core" smokers who persist in their smoking habits despite the serious health consequences incurred by continued smoking. This population of smokers may require a more intensive, specialized intervention to achieve smoking cessation.

Systematizing inpatient referral to cardiac rehabilitation 2010: Canadian Association of Cardiac Rehabilitation and Canadian Cardiovascular Society joint position paper endorsed by the Cardiac Care Network of Ontario.

Despite recommendations in clinical practice guidelines, evidence suggests cardiac rehabilitation (CR) referral and use following indicated cardiac events is low. Referral strategies such as systematic referral have been advocated to improve CR use. The objective of this policy position is to synthesize evidence and make recommendations on strategies to increase patient enrollment in CR. A systematic review of 6 databases from inception to January 2009 was conducted. Only primary, published, English-language studies were included. A meta-analysis was undertaken to synthesize the enrollment rates by referral strategy. In all, 14 studies met inclusion criteria. Referral strategies were categorized as systematic on the basis of use of systematic discharge order sets, as liaison on the basis of discussions with allied health care providers, or as other on the basis of patient letters. Overall, there were 7 positive studies, 5 without comparison groups, and 2 studies that reported null findings. The combined effect sizes of the meta-analysis were as follows: 73% (95% CI, 39%-92%) for the patient letters ("other"), 66% (95% CI, 54%-77%) for the combined systematic and liaison strategy, 45% (95% CI, 33%-57%) for the systematic strategy alone, and 44% (95% CI, 35%-53%) for the liaison strategy alone. In conclusion, the results suggest that innovative referral strategies increase CR use. Although patient letters look promising, evidence for this strategy is sparse and inconsistent at present. Therefore we suggest that inpatient units adopt systematic referral strategies, including a discussion at the bedside, for eligible patient groups in order to increase CR enrollment and participation. This approach should be considered best practice for further investigation.

Systematizing Inpatient Referral to Cardiac Rehabilitation 2010: Canadian association of cardiac rehabilitation and Canadian cardiovascular society joint position paper.

Despite recommendations in clinical practice guidelines, evidence suggests cardiac rehabilitation (CR) referral and use following indicated cardiac events is low. Referral strategies such as systematic referral have been advocated to improve CR use. The objective of this policy position is to synthesize evidence and make recommendations on strategies to increase patient enrollment in CR. A systematic review of 6 databases from inception to January 2009 was conducted. Only primary, published, English-language studies were included. A meta-analysis was undertaken to synthesize the enrollment rates by referral strategy. In all, 14 studies met inclusion criteria. Referral strategies were categorized as systematic on the basis of use of systematic discharge order sets, as liaison on the basis of discussions with allied health care providers, or as other on the basis of patient letters. Overall, there were 7 positive studies, 5 without comparison groups, and 2 studies that reported null findings. The combined effect sizes of the meta-analysis were as follows: 73% (95% CI, 39%-92%) for the patient letters ("other"), 66% (95% CI, 54%-77%) for the combined systematic and liaison strategy, 45% (95% CI, 33%-57%) for the systematic strategy alone, and 44% (95% CI, 35%-53%) for the liaison strategy alone. In conclusion, the results suggest that innovative referral strategies increase CR use. Although patient letters look promising, evidence for this strategy is sparse and inconsistent at present. Therefore we suggest that inpatient units adopt systematic referral strategies, including a discussion at the bedside, for eligible patient groups in order to increase CR enrollment and participation. This approach should be considered best practice for further investigation.

Comparison of gas exchange data using the Aquatrainer system and the facemask with Cosmed K4b2 during exercise in healthy subjects.

The aim of this study was to determine the level of agreement between the new Aquatrainer system and the facemask in the assessment of submaximal and maximal cardiopulmonary responses during exercise performed on ergocycle. Twenty-six physically active healthy subjects (mean age: 41 +/- 14 years) performed a submaximal constant work test followed by maximal incremental exercise test on ergocycle, one with cardiopulmonary responses measured using the Cosmed K4b2 facemask, the other using the Cosmed K4b2 Aquatrainer. Using the Aquatrainer, the gas exchange variables at 100 W were significantly lower for VO(2) (1,483 +/- 203 vs. 1,876 +/- 204 ml min(-1), P < 0.0001), VCO(2) (1,442 +/- 263 vs. 1,749 +/- 231 ml min(-1), P < 0.0001), VE (38 +/- 5 vs. 44 +/- 6 l min(-1), P < 0.0001), and VT (1.92 +/- 0.47 vs. 2.18 +/- 0.41 l, P < 0.0001) relative to facemask. The bias +/-95% limits of agreement (LOA) for VO(2) was 393 +/- 507 ml min(-1) for the submaximal constant work test at 100 W and 495 +/- 727 ml min(-1) for VO(2max). At maximal intensity, cardiopulmonary responses measured with the Aquatrainer system were significantly lower for: VO(2) (2,799 +/- 751 vs. 3,294 +/- 821 ml min(-1), P < 0.0001), VCO(2) (3,426 +/- 836 vs. 3,641 +/- 946 ml min(-1), P = 0.012), VE (98 +/- 21 vs. 108 +/- 26 l min(-1), P = 0.0009) relative to facemask. A non-constant measurement error [interaction effect: (facemask or aquatrainer) x power] was noted from 60 to 270 W for VO(2) (ml min(-1)), VCO(2) (ml min(-1)), ventilation (l min(-1)) (P < 0.0001) and VT (l, P = 0.0001). Additional studies are required to detect the main sources of error that could be physical and/or physiological in nature. Due to the significant measurement error, the new Aquatrainer system should be used with extreme caution in filed testing conditions of swimmers.

Implementation and outcomes of a comprehensive worksite health promotion program.

BACKGROUND: This paper reports on the implementation and results of a three-year comprehensive worksite health promotion program called Take care of your health!, delivered at a single branch of a large financial organization with 656 employees at the beginning of the implementation period and 905 at the end. The program included six educational modules delivered over a three-year period. A global health profile was part of the first and last modules. The decision to implement the program coincided with an overall program of organizational renewal. METHODS: The data for this evaluation come from four sources: analysis of changes in employee health profiles between the first and last program sessions (n=270); questionnaires completed by participating employees at the end of the program (n=169); organizational data on employee absenteeism and turnover; and qualitative interviews with company managers (n=9). RESULTS: Employee participation rates in the six modules varied between 39% and 76%. The assessment of health profile changes showed a significant increase in the Global Health Score. Participants were significantly more likely to report more frequent physical activity and better nutritional practices. The proportion of smokers among participants was significantly reduced (p = 0.0147). Also reduced significantly between the two measurements were self-assessment of high stress inside and outside the workplace, stress signs, and feelings of depression. Employees were highly satisfied with the program and felt that it had impacts on their knowledge and capacities to manage their health behaviour. During the same period, absenteeism in the organization declined by 28% and turnover by 54%. From the organization's perspective, program implementation was very successful. CONCLUSIONS: This study's results are in line with previous findings of significant benefits to organizations and employees from worksite health promotion. The close relationship between the program outcomes and the overall process of organizational renewal that it accompanied supports previous arguments that worksite health promotion will be most effective when it promotes overall organizational health.

Long-term cardiac rehabilitation and exercise training programs improve metabolic parameters in metabolic syndrome patients with and without coronary heart disease.

BACKGROUND AND AIMS: The effectiveness of long-term cardiac rehabilitation and exercise training programs on metabolic parameters was evaluated in metabolic syndrome subjects with and without coronary heart disease (CHD). METHODS AND RESULTS: Fifty-nine CHD and 81 non-coronary patients with metabolic syndrome (59+/-8 vs 56+/-9years) were identified retrospectively at entry into identical cardiac rehabilitation and exercise-training programs. Metabolic syndrome was defined using modified Adult Treatment Panel III criteria. Exercise training occurred approximately twice per week. Metabolic and exercise testing data were collected at baseline and after 12months during the course of the program. Mean duration of cardiac rehabilitation and exercise training programs was over one year in both coronary and non-coronary patients (366+/-111 vs 414+/-102days for CHD and non-coronary CHD cohorts respectively, p<0.01). Significant improvements in bodyweight, body mass index, blood lipids, triglyceride/HDL ratio and exercise tolerance were noted in both cohorts. At the end of follow-up, 31% of CHD and 20% of non-CHD subjects no longer possessed diagnostic criteria for metabolic syndrome (p<0.0001 and p<0.001 respectively). CONCLUSIONS: A long-term cardiac rehabilitation program reduces metabolic syndrome prevalence in CHD patients and results in a similar improvement in risk factor control for metabolic syndrome patients without CHD.

Improvement in exercise capacity in asymptomatic and mildly symptomatic adults after atrial septal defect percutaneous closure.

BACKGROUND: Controversy exists as to whether secundum atrial septal defects (ASDs) in asymptomatic or mildly symptomatic New York Heart Association (NYHA) class I or II adult patients should be closed. METHODS AND RESULTS: Thirty-seven patients (24 females; mean age 49.4 years, range 19 to 76) with a mean pulmonary to systemic flow ratio (Qp:Qs) of 2.1 (1.2 to 3.4) had a maximal oxygen uptake (VO2max) determination and echocardiographic measurement of right ventricular dimensions before and 6 months after elective percutaneous closure of ASD. At baseline, mean VO2max was 23.5+/-6.4 mL/kg per minute and was higher in the 15 NYHA I patients than in the 22 NYHA II patients (27+/-6.9 versus 20.8+/-4.6 mL/kg per minute; P=0.0015). VO2max increased significantly at 6 months (23.5+/-6.4 to 26.9+/-6.9 mL/kg per minute; P<0.0001). Improvement was as marked in NYHA I (+22%; P<0.0001) as in NYHA II patients (+12%; P<0.0001), in patients with Qp:Qs 1.2 to 2.0 (+16%; P<0.0001) as in those with Qp:Qs >2 (+12%; P<0.0001), and in patients > or =40 years of age (+14%; P<0.0001) as in those <40 years of age (+16%; P<0.0001). Compared with 15 of 37 patients before closure, 35 of 37 patients were in NYHA I at 6 months. Right ventricular dimensions decreased significantly (P<0.0001). CONCLUSIONS: Adult ASD patients significantly increase their functional capacity after percutaneous defect closure. This is observed even in patients classified as asymptomatic, in those with lesser shunts, and in older patients. These findings suggest that ASD closure in an adult population should be considered even in the absence of symptoms.