Participation in cardiac rehabilitation, readmissions, and death after acute myocardial infarction

BACKGROUND

Participation in cardiac rehabilitation has been shown to decrease mortality after acute myocardial infarction, but its impact on readmissions requires examination.

METHODS

We conducted a population-based surveillance study of residents discharged from the hospital after their first-ever myocardial infarction in Olmsted County, Minnesota, from January 1, 1987, to September 30, 2010. Patients were followed up through December 31, 2010. Participation in cardiac rehabilitation after myocardial infarction was determined using billing data. We used a landmark analysis approach (cardiac rehabilitation participant vs not determined by attendance in at least 1 session of cardiac rehabilitation at 90 days post-myocardial infarction discharge) to compare readmission and mortality risk between cardiac rehabilitation participants and nonparticipants accounting for propensity to participate using inverse probability treatment weighting.

RESULTS

Of 2991 patients with incident myocardial infarction, 1569 (52.5%) participated in cardiac rehabilitation after hospital discharge. The cardiac rehabilitation participation rate did not change during the study period, but increased in the elderly and decreased in men and younger patients. After adjustment, cardiac rehabilitation participants had lower all-cause readmission (hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.65-0.87; P < .001), cardiovascular readmission (HR, 0.80; 95% CI, 0.65-0.99; P = .037), noncardiovascular readmission (HR, 0.72; 95% CI, 0.61-0.85; P < .001), and mortality (HR, 0.58; 95% CI, 0.49-0.68; P < .001) risk.

CONCLUSIONS

Cardiac rehabilitation participation is associated with a markedly reduced risk of readmission and death after incident myocardial infarction. Improving cardiac rehabilitation participation rates may have a large impact on post-myocardial infarction healthcare resource use and outcomes.

Self-rated health predicts healthcare utilization in heart failure

Background

Heart failure (HF) patients experience impaired functional status, diminished quality of life, high utilization of healthcare resources, and poor survival. Yet, the identification of patient‐centered factors that influence prognosis is lacking.

Methods and Results

We determined the association of 2 measures of self‐rated health with healthcare utilization and skilled nursing facility (SNF) admission in a community cohort of 417 HF patients prospectively enrolled between October 2007 and December 2010 from Olmsted County, MN. Patients completed a 12‐item Short Form Health Survey (SF‐12). Low self‐reported physical functioning was defined as a score ≤25 on the SF‐12 physical component. The first question of the SF‐12 was used as a measure of self‐rated general health. After 2 years, 1033 hospitalizations, 1407 emergency department (ED) visits, and 19,780 outpatient office visits were observed; 87 patients were admitted to a SNF. After adjustment for confounding factors, an increased risk of hospitalizations (1.52 [1.17 to 1.99]) and ED visits (1.48 [1.04 to 2.11]) was observed for those with low versus moderate‐high self‐reported physical functioning. Patients with poor and fair self‐rated general health also experienced an increased risk of hospitalizations (poor: 1.73 [1.29 to 2.32]; fair: 1.46 [1.14 to 1.87]) and ED visits (poor: 1.73 [1.16 to 2.56]; fair: 1.48 [1.13 to 1.93]) compared with good‐excellent self‐rated general health. No association between self‐reported physical functioning or self‐rated general health with outpatient visits and SNF admission was observed.

Conclusion

In community HF patients, self‐reported measures of physical functioning predict hospitalizations and ED visits, indicating that these patient‐reported measures may be useful in risk stratification and management in HF.

Resuscitation preferences in community patients with heart failure

BACKGROUND

Little is known about the resuscitation preferences of patients with heart failure, how they may change over the course of the disease, and their association with mortality.

METHODS AND RESULTS

We enrolled consecutive Southeastern Minnesota residents with heart failure from October 2007 through September 2011 into a longitudinal study. Information on resuscitation preferences (Full Code or do-not-resuscitate [DNR]) was obtained from medical records through April 1, 2013. Of 608 patients enrolled, 237 died during follow-up. At enrollment, most patients (73.4%) were Full Code, whereas at death, most (78.5%) were DNR. The independent predictors of DNR status at enrollment were advanced age, chronic obstructive pulmonary disease, previous malignancy, and decreased mobility. Patients who were DNR were at increased risk of death (unadjusted hazard ratio, 2.03; 95% confidence interval, 1.48-2.73; P<0.001), but this risk did not persist after adjusting for age, comorbidity, and self-perceived general health (hazard ratio, 0.97; 95% confidence interval, 0.74-1.30; P=0.83). Of 481 patients who were Full Code during follow-up, 22 (4.6%) received cardiopulmonary resuscitation for an in-hospital cardiac arrest. Eight patients survived to hospital discharge; only 2 (9.1% of those receiving cardiopulmonary resuscitation) made a complete recovery and returned home. The median time from a final decision to be DNR until death was only 37 (7,70) days.

CONCLUSIONS

The resuscitation preferences of patients with heart failure seem to be driven by the decline in clinical status that often accompanies advanced age and multimorbidity. Furthermore, these data suggest that electing DNR status does not independently affect a patient's risk of death.

Frailty and outcomes after implantation of left ventricular assist device as destination therapy

BACKGROUND

Frailty is recognized as a major prognostic indicator in heart failure. There has been interest in understanding whether pre-operative frailty is associated with worse outcomes after implantation of a left ventricular assist device (LVAD) as destination therapy.

METHODS

Patients undergoing LVAD implantation as destination therapy at the Mayo Clinic, Rochester, Minnesota, from February 2007 to June 2012, were included in this study. Frailty was assessed using the deficit index (31 impairments, disabilities and comorbidities) and defined as the proportion of deficits present. We divided patients based on tertiles of the deficit index (>0.32 = frail, 0.23 to 0.32 = intermediate frail, <0.23 = not frail). Cox proportional hazard regression models were used to examine the association between frailty and death. Patients were censored at death or last follow-up through October 2013.

RESULTS

Among 99 patients (mean age 65 years, 18% female, 55% with ischemic heart failure), the deficit index ranged from 0.10 to 0.65 (mean 0.29). After a mean follow-up of 1.9 ± 1.6 years, 79% of the patients had been rehospitalized (range 0 to 17 hospitalizations, median 1 per person) and 45% had died. Compared with those who were not frail, patients who were intermediate frail (adjusted HR 1.70, 95% CI 0.71 to 4.31) and frail (HR 3.08, 95% CI 1.40 to 7.48) were at increased risk for death (p for trend = 0.004). The mean (SD) number of days alive out of hospital the first year after LVAD was 293 (107) for not frail, 266 (134) for intermediate frail and 250 (132) for frail patients.

CONCLUSIONS

Frailty before destination LVAD implantation is associated with increased risk of death and may represent a significant patient selection consideration.

Brief report: accelerated aging influences cardiovascular disease risk in rheumatoid arthritis

OBJECTIVE

To determine whether the impact of aging on cardiovascular disease (CVD) risk in patients with rheumatoid arthritis (RA) differs from that in the general population (as estimated by the Framingham Risk Score [FRS]).

METHODS

A population-based inception cohort of Olmsted County, Minnesota residents ages≥30 years who fulfilled the American College of Rheumatology 1987 criteria for RA in 1988-2008 was assembled and followed up until death, migration, or July 1, 2012. Data on CVD events were collected by medical records review. The 10-year FRS for CVD was calculated. Cox models adjusted for FRS were used to examine the influence of age on CVD risk.

RESULTS

The study included 563 patients with RA without prior CVD (mean age 55 years, 72% women, and 69% seropositive [i.e., rheumatoid factor and/or anti-citrullinated protein antibody positive]). During a mean followup of 8.2 years, 98 patients developed CVD (74 seropositive and 24 seronegative), but the FRS predicted only 59.7 events (35.4 seropositive and 24.3 seronegative). The gap between observed and predicted CVD risk increased exponentially across age, and the effect of age on CVD risk in seropositive RA was nearly double its effect in the general population, with additional log(age) coefficients of 2.91 for women (P=0.002) and 2.06 for men (P=0.027).

CONCLUSION

Our findings indicate that age exerts an exponentially increasing effect on CVD risk in seropositive RA, but no increased effect among seronegative patients. The causes of accelerated aging in patients with seropositive RA deserve further investigation.

Epidemiology of heart failure

Heart failure (HF) has been singled out as an epidemic and is a staggering clinical and public health problem, associated with significant mortality, morbidity, and healthcare expenditures, particularly among those aged ≥ 65 years. The case mix of HF is changing over time with a growing proportion of cases presenting with preserved ejection fraction for which there is no specific treatment. Despite progress in reducing HF-related mortality, hospitalizations for HF remain frequent and rates of readmissions continue to rise. To prevent hospitalizations, a comprehensive characterization of predictors of readmission in patients with HF is imperative and must integrate the impact of multimorbidity related to coexisting conditions. New models of patient-centered care that draw on community-based resources to support HF patients with complex coexisting conditions are needed to decrease hospitalizations.

Contemporary trends in heart failure with reduced and preserved ejection fraction after myocardial infarction: a community study

Major changes have recently occurred in the epidemiology of myocardial infarction (MI) that could possibly affect outcomes such as heart failure (HF). Data describing trends in HF after MI are scarce and conflicting and do not distinguish between preserved and reduced ejection fraction (EF). We evaluated temporal trends in HF after MI. All residents of Olmsted County, Minnesota (n = 2,596) who had a first-ever MI diagnosed in 1990-2010 and no prior HF were followed-up through 2012. Framingham Heart Study criteria were used to define HF, which was further classified according to EF. Both early-onset (0-7 days after MI) and late-onset (8 days to 5 years after MI) HF were examined. Changes in patient presentation were noted, including fewer ST-segment-elevation MIs, lower Killip class, and more comorbid conditions. Over the 5-year follow-up period, 715 patients developed HF, 475 of whom developed it during the first week. The age- and sex-adjusted risk declined from 1990-1996 to 2004-2010, with hazard ratios of 0.67 (95% confidence interval (CI): 0.54, 0.85) for early-onset HF and 0.63 (95% CI: 0.45, 0.86) for late-onset HF. Further adjustment for patient and MI characteristics yielded hazard ratios of 0.86 (95% CI: 0.66, 1.11) and 0.63 (95% CI: 0.45, 0.88) for early- and late-onset HF, respectively. Declines in early-onset and late-onset HF were observed for HF with reduced EF (<50%) but not for HF with preserved EF, indicating a change in the case mix of HF after MI that requires new prevention strategies.

Atrial fibrillation in myocardial infarction patients: Impact on health care utilization

BACKGROUND

Atrial fibrillation (AF) often complicates myocardial infarction (MI). While AF adversely impacts survival in MI patients, the impact of AF on health care utilization has not been studied.

METHODS

The risk of hospitalizations, emergency department (ED) visits, and outpatient visits associated with prior, new-onset (<30 days post-MI), and late-onset (≥30 days post-MI) AF was assessed among incident MI patients from the Olmsted County, Minnesota, community.

RESULTS

Of 1,502 MI patients, 237 had prior AF, 163 developed new-onset AF, 113 developed late-onset AF, and 989 had no AF. Over a mean follow-up of 3.9 years, 3,661 hospitalizations, 5,559 ED visits, and 80,240 outpatient visits occurred. After adjustment, compared with patients without AF, those with prior and new-onset AF exhibited a 1.6-fold and 1.3-fold increased risk of hospitalization, respectively. In contrast, late-onset AF carried a 2.2-fold increased risk of hospitalization. The hazard ratios were 1.4, 1.2, and 1.8 for ED visits and 1.4, 1.2, and 1.7 for outpatient visits for prior, new-onset, and late-onset AF. Additional adjustment for time-dependent recurrent MI and heart failure attenuated the results slightly for hospitalizations and ED visits; however, patients with late-onset AF still exhibited a >50% increased risk for both utilization measures.

CONCLUSIONS

In MI patients, the risk of hospitalizations, ED visits, and outpatient visits differed by the timing of AF onset, with the greatest risk conferred by late-onset AF. Atrial fibrillation imparts an adverse prognosis after MI, underscoring the importance of its management in MI patients.

Measuring frailty in heart failure: a community perspective

BACKGROUND

Frailty, an important prognostic indicator in heart failure (HF), may be defined as a biological phenotype or an accumulation of deficits. Each method has strengths and limitations, but their utility has never been evaluated in the same community HF cohort.

METHODS

Southeastern Minnesota residents with HF were recruited from 2007 to 2011. Frailty according to the biological phenotype was defined as 3 or more of: weak grip strength, physical exhaustion, slowness, low activity and unintentional weight loss >10 lb in 1 year. Intermediate frailty was defined as 1 to 2. The deficit index was defined as the proportion of deficits present out of 32 deficits.

RESULTS

Among 223 patients (mean age 71 ± 14, 61% male), 21% were frail and 48% intermediate frail according to the biological phenotype. The deficit index ranged from 0.02-0.75, with a mean (SD) of 0.25 (0.13). Over a mean follow-up of 2.4 years, 63 patients died. After adjustment for age, sex and ejection fraction, patients categorized as frail by the biological phenotype had a 2-fold increased risk of death compared to those with no frailty, whereas a 0.1 unit increase in the deficit index was associated with a 44% increased risk of death. Both measures predicted death equally (C-statistics: 0.687 for biological phenotype and 0.700 for deficit index).

CONCLUSION

The deficit index and the biological phenotype equally predict mortality. As the biological phenotype is not routinely assessed clinically, the deficit index, which can be ascertained from medical records, is a feasible alternative to ascertain frailty.

Brief report: rheumatoid arthritis is associated with left ventricular concentric remodeling: results of a population-based cross-sectional study

OBJECTIVE

To study left ventricular (LV) geometry in patients with rheumatoid arthritis (RA) and no history of heart failure compared with that in subjects with neither RA nor a history of heart failure, and to determine the impact of RA on LV remodeling.

METHODS

A cross-sectional, community-based study was conducted among adult (age ≥50 years) patients with RA and age- and sex-matched subjects with neither RA nor a history of heart failure. All participants underwent standard 2-dimensional Doppler echocardiography. LV geometry was classified into the following 4 categories based on relative wall thickness and sex-specific cutoffs for the LV mass index: concentric remodeling, concentric hypertrophy, eccentric hypertrophy, or normal geometry.

RESULTS

Among 200 patients with RA and 600 age- and sex-matched subjects without RA, the mean age was 65 years, and 74% of the individuals in both cohorts were female. Compared with subjects without RA, patients with RA were significantly more likely to have abnormal LV geometry (odds ratio [OR] 1.44, 95% confidence interval [95% CI] 1.03-2.00), even after adjusting for cardiovascular risk factors and comorbidities. Among subjects with abnormal LV geometry, the odds of concentric LV remodeling were significantly increased in patients with RA (OR 4.73, 95% CI 2.85-7.83). In linear regression analyses, the LV mass index appeared to be lower in patients with RA who were currently receiving corticosteroids (β ± SE -0.082 ± 0.027, P = 0.002), even after adjusting for cardiovascular risk factors and comorbidities.

CONCLUSION

RA was strongly associated with abnormal LV remodeling (particularly concentric LV remodeling) among RA patients without heart failure. This association remained significant after adjustment for cardiovascular risk factors and comorbidities. RA disease-related factors may promote changes in LV geometry. The biologic mechanisms underlying LV remodeling warrant further investigation.

Frailty and health-related quality of life among residents of long-term care facilities

OBJECTIVE

To determine the prevalence and relationship of frailty and health-related quality of life (HRQOL) among residents of long-term care [nursing homes (NH) and assisted living (AL)] facilities.

METHODS

Residents of NH and AL facilities in La Crosse County, Wisconsin, were recruited 1/2009-6/2010 and assessed for frailty (gait speed, unintended weight loss, grip strength), comorbidity (Charlson index), and HRQOL [Short Form (SF)-36].

RESULTS

Among 137 participants, 85% were frail. Frail residents were older, had more comorbidities (2.0 vs. 0, p < .001) and lower mean SF-36 Physical Component Score (PCS, 32 vs. 48, p < .001). Following adjustments for age, sex, and comorbidities, compared to nonfrail residents, frail residents had lower SF-36 PCS (mean difference -14.7, 95% CI. -19.3,-10.1, p < .001). Frailty, comorbidity, and HRQOL did not differ between NH and AL facilities.

DISCUSSION

Frail residents had lower HRQOL, suggesting that preventing frailty may lead to better HRQOL among residents of long-term care facilities.

Temporal relationship and prognostic significance of atrial fibrillation in heart failure patients with preserved ejection fraction: a community-based study

BACKGROUND

In patients with heart failure and preserved ejection fraction (HFpEF), atrial fibrillation (AF) may predate, concur with, or develop after HFpEF diagnosis. We sought to define the temporal relationship between AF and HFpEF, to identify factors associated with AF, and to determine the prognostic impact of prevalent and incident AF in HFpEF.

METHOD AND RESULTS

From 1983 to 2010, 939 Olmsted County, Minnesota, residents (age, 77±12 years; 61% female) newly diagnosed with HFpEF (EF ≥0.50) were evaluated. Baseline rhythm classification included prior AF (>3 months before HFpEF diagnosis), concurrent AF (±3 months), or sinus rhythm. Incident AF (>3 months after HFpEF diagnosis) and all-cause mortality were ascertained through February 2012. Prior AF (29%) and concurrent AF (23%) were associated with older age, higher brain-type natriuretic peptide, and larger left atrial volume index at HFpEF diagnosis compared with sinus rhythm. Of HFpEF patients in sinus rhythm at diagnosis, 32% developed AF over a median follow-up of 3.7 years (interquartile range, 1.5-6.7 years; 69 events per 1000 person-years). Age and diastolic dysfunction were positively and statin use was inversely associated with incident AF. With no AF used as the referent, prior or concurrent AF (combined hazard ratio, 1.3; 95% confidence interval, 1.0-1.6; P=0.03) and incident AF, modeled as a time-dependent covariate (hazard ratio, 2.1; 95% confidence interval, 1.4-3.0; P<0.001), were independently associated with death after adjustment for pertinent covariates.

CONCLUSIONS

AF occurs in two thirds of HFpEF patients at some point in the natural history and confers a poor prognosis. Further study is required to determine whether intervention for AF may improve outcomes or if statin use can prevent AF in HFpEF.

Heart failure performance measures: eligibility and implementation in the community

BACKGROUND

The goal of heart failure (HF) performance measures is to improve quality of care by assessing the implementation of guidelines in eligible patients. Little is known about the proportion of eligible patients and how performance measures are implemented in the community.

METHODS

We determined the eligibility for and adherence to performance measures and β-blocker therapy in a community-based cohort of hospitalized HF patients from January 2005 to June 2011.

RESULTS

All of the 465 HF inpatients (median age 76 years, 48% men) included in the study received an ejection fraction assessment. Only 164 had an ejection fraction <40% thus were candidates for β-blocker and angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blocker (ARB) therapy. Considering absolute contraindications, 99 patients were eligible to receive ACE inhibitors/ARB, and 162 to receive β-blockers. Among these, 85% received ACE inhibitors/ARBs and 91% received β-blockers. Among the 261 individuals with atrial fibrillation, 89 were eligible for warfarin and 54% received it. Of 52 current smokers, 69% received cessation counseling during hospitalization.

CONCLUSION

In the community, among eligible hospitalized HF patients, the implementation of performance measures can be improved. However, as most patients are not candidates for current performance measures, other approaches are needed to improve care and outcomes.

Age and sex patterns of drug prescribing in a defined American population

OBJECTIVE

To describe the age and sex patterns of drug prescribing in Olmsted County, Minnesota.

PATIENTS AND METHODS

Population-based drug prescription records for the Olmsted County population in 2009 were obtained using the Rochester Epidemiology Project medical records linkage system (n=142,377). Drug prescriptions were classified using RxNorm codes and were grouped using the National Drug File-Reference Terminology.

RESULTS

Overall, 68.1% of the population (n=96,953) received a prescription from at least 1 drug group, 51.6% (n=73,501) received prescriptions from 2 or more groups, and 21.2% (n=30,218) received prescriptions from 5 or more groups. The most commonly prescribed drug groups in the entire population were penicillins and β-lactam antimicrobials (17%; n=23,734), antidepressants (13%; n=18,028), opioid analgesics (12%; n=16,954), antilipemic agents (11%; n=16,082), and vaccines/toxoids (11%; n=15,918). However, prescribing patterns differed by age and sex. Vaccines/toxoids, penicillins and β-lactam antimicrobials, and antiasthmatic drugs were most commonly prescribed in persons younger than 19 years. Antidepressants and opioid analgesics were most commonly prescribed in young and middle-aged adults. Cardiovascular drugs were most commonly prescribed in older adults. Women received more prescriptions than men for several drug groups, in particular for antidepressants. For several drug groups, use increased with advancing age.

CONCLUSION

This study provides valuable baseline information for future studies of drug utilization and drug-related outcomes in this population.

Gender differences in the pathophysiology, clinical presentation, and outcomes of ischemic heart failure

Despite advances in the treatment of acute myocardial infarction (MI), heart failure (HF) remains a frequent acute and long-term outcome of ischemic heart disease (IHD). In response to acute coronary ischemia, women are relatively protected from apoptosis, and experience less adverse cardiac remodeling than men, frequently resulting in preservation of left ventricular size and ejection fraction. Despite these advantages, women are at increased risk for HF- complicating acute MI when compared with men. However, women with HF retain a survival advantage over men with HF, including a decreased risk of sudden death. Sex-specific treatment of HF has been hindered by historical under-representation of women in clinical trials, though recent work has suggested that women may have a differential response to some therapies such as cardiac resynchronization. This review highlights the sex differences in the pathophysiology, clinical presentation and outcomes of ischemic heart failure and discusses key areas worthy of further investigation.

Physical health status measures predict all-cause mortality in patients with heart failure

BACKGROUND

Physical health status measures have been shown to predict death in heart failure (HF); however, few studies found significant associations after adjustment for confounders, and most were not representative of all HF patients.

METHODS AND RESULTS

HF patients from southeastern MN were prospectively enrolled between 10/2007 and 12/2010, completed a 12-item Short Form Health Survey (SF-12) and a 6-minute walk, and were followed through 2011 for death from any cause. Scores ≤ 25 on the SF-12 physical component indicated low self-reported physical functioning, and the first question of the SF-12 measured self-rated general health. Low functional exercise capacity was defined as ≤ 300 m walked during a 6-minute walk. Over a mean follow-up of 2.3 years, 86 deaths occurred among the 352 participants. A 1.6-fold (95% confidence interval, 1.0-2.7) and 1.8-fold (95% confidence interval, 1.1-2.9) increased risk of death was observed among patients with low self-reported physical functioning and low functional exercise capacity, respectively. Poor self-rated general health corresponded to a 2.7-fold (95% confidence interval, 1.5-4.9) increased risk of death compared with good to excellent general health. All measures equally discriminated between who would die and who would survive (C-statistics: 0.729, 0.750, and 0.740 for self-reported physical functioning, self-rated general health, and functional exercise capacity, respectively).

CONCLUSIONS

Three physical health status measures, captured by the SF-12 and a 6-minute walk, equally predict death among community HF patients. Therefore, the first question of the SF-12, which is the least burdensome to administer, may be sufficient to identify HF patients at greatest risk of death.

Myocardial infarction and sudden cardiac death in Olmsted County, Minnesota, before and after smoke-free workplace laws

BACKGROUND

Reductions in admissions for myocardial infarction (MI) have been reported in locales where smoke-free workplace laws have been implemented, but no study has assessed sudden cardiac death in that setting. In 2002, a smoke-free restaurant ordinance was implemented in Olmsted County, Minnesota, and in 2007, all workplaces, including bars, became smoke free.

METHODS

To evaluate the population impact of smoke-free laws, we measured, through the Rochester Epidemiology Project, the incidence of MI and sudden cardiac death in Olmsted County during the 18-month period before and after implementation of each smoke-free ordinance. All MIs were continuously abstracted and validated, using rigorous standardized criteria relying on biomarkers, cardiac pain, and Minnesota coding of the electrocardiogram. Sudden cardiac death was defined as out-of-hospital deaths associated with coronary disease.

RESULTS

Comparing the 18 months before implementation of the smoke-free restaurant ordinance with the 18 months after implementation of the smoke-free workplace law, the incidence of MI declined by 33% (P < .001), from 150.8 to 100.7 per 100,000 population, and the incidence of sudden cardiac death declined by 17% (P = .13), from 109.1 to 92.0 per 100,000 population. During the same period, the prevalence of smoking declined and that of hypertension, diabetes mellitus, hypercholesterolemia, and obesity either remained constant or increased.

CONCLUSIONS

A substantial decline in the incidence of MI was observed after smoke-free laws were implemented, the magnitude of which is not explained by community cointerventions or changes in cardiovascular risk factors with the exception of smoking prevalence. As trends in other risk factors do not appear explanatory, smoke-free workplace laws seem to be ecologically related to these favorable trends. Secondhand smoke exposure should be considered a modifiable risk factor for MI. All people should avoid secondhand smoke to the extent possible, and people with coronary heart disease should have no exposure to secondhand smoke.