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Background: During the past quarter century, advances in treatment of cardiovascular disease have occurred that might potentially benefit survivors of sudden cardiac arrest (SCA). Little is known, however, about the temporal patterns in long-term survival among persons resuscitated from SCA. We hypothesized that long-term survival would improve over time and that this temporal pattern would be most evident for cardiac causes of death., Methods and Results: The investigation was a retrospective cohort study of survival among persons who were discharged alive from the hospital after resuscitation from out-of-hospital SCA due to heart disease in King County, Wash, between May 1, 1976, and December 31, 2001 (n=2035). Calendar time was divided into four 5-year intervals: 1976 to 1980, 1981 to 1985, 1986 to 1990, and 1991 to 1995, and one 6-year interval, 1996 to 2001. Age-adjusted survival curves were constructed, and Cox proportional-hazards regression was used to compute hazard ratios (HRs) for the association between mortality and time period. During 11 201 person-years of follow-up, 1334 persons died. Compared with the initial time period, the HR for total mortality was 0.86 (95% confidence interval, 0.73 to 1.01) for 1981 to 1985, 0.82 (0.69 to 0.96) for 1986 to 1990, 0.66 (0.55 to 0.79) for 1991 to 1995, and 0.58 (0.47 to 0.71) for 1996 to 2001 (HR for trend=0.87 [0.84 to 0.91] for each successive time period). In analyses that assessed cardiac mortality, an even stronger temporal association was evident (HR for trend=0.79 [0.75 to 0.84])., Conclusions: Long-term survival after resuscitation from SCA improved steadily over time in this cohort. To continue this trend, future studies should identify circumstances in which proven treatments are underutilized as well as investigate new therapies that might benefit survivors of SCA.

We hypothesized that possession of either of 2 functional coagulation factor XIII polymorphisms, one within subunit A (Val34Leu) and one within subunit B (His95Arg), might modulate the prothrombotic effects of estrogen and help to explain the variation in incidence of arterial thrombotic events among postmenopausal women using hormone replacement therapy. In a population-based case-control study of 955 postmenopausal women, we assessed the associations of factor XIII genotypes and their interactions with estrogen therapy on risk of nonfatal myocardial infarction (MI). The presence of the factor XIIIA Leu34 allele was associated with a reduced risk of MI (odds ratio [OR] = 0.70, 95% confidence interval [95% CI] = 0.51-0.95). The presence of the factor XIIIB Arg95 allele had little association with MI risk. Neither factor XIII polymorphism alone significantly modified the association between the risk of MI and current estrogen use. In exploratory analyses, however, there was a significant factor XIII subunit gene-gene interaction. Compared to women homozygous for both common factor XIII alleles, the Arg95 variant was associated with a reduced risk of MI in the presence of the Leu34 variant (OR = 0.36, 95% CI = 0.17-0.75) but not in the absence of the Leu34 variant (OR = 1.11, 95% CI = 0.69-1.79). Moreover, among women who had at least 2 copies of the variant factor XIII alleles and were current estrogen users, the risk of MI was reduced by 70% relative to estrogen nonusers with fewer than 2 factor XIII variant alleles (P value for interaction =.03). If confirmed, these findings may permit a better assessment of the cardiovascular risks and benefits associated with postmenopausal estrogen therapy.

Background and Objective: The cardiac safety of digoxin therapy for congestive heart failure (CHF) is a source of concern, especially among those with renal impairment., Methods: Using a case-control design, we examined the risk of primary cardiac arrest (PCA) associated with digoxin therapy within three levels of renal function., Results: After adjustment for other clinical characteristics, digoxin therapy for CHF was not associated with an increased risk of PCA [odds ratio (OR)=0.97, 95% confidence interval (CI) 0.59-1.62] among patients with normal renal function (serum creatinine

Background: A considerable number of emergency medical services (EMS) responses for cardiac arrest occur in long-term care facilities. In some instances, these responses are for residents who have expressed wishes not to be resuscitated by signing a do not resuscitate (DNR) order., Objectives: To assess the magnitude of EMS use for cardiac arrest in long-term care facilities for residents with DNR orders and to determine reasons why EMS is called., Methods: A retrospective study was conducted using data collected from medical incident reports between July 1999 and December 2000 for all persons experiencing cardiac arrest in long-term care facilities defined as nursing homes, adult family homes, and assisted-living centers in King County, Washington, excluding Seattle. The authors also surveyed facilities to determine their policies for calling 9-1-1 in the event of cardiac arrest. Results. Of the 392 cardiac arrests in long-term care facilities to which EMS responded, 139 (35%) of the residents had DNR orders. Of these 139, 29 (21%) received attempted resuscitation by EMS. The problem appeared to be greater among nursing homes and adult family homes than in assisted-living centers. Among nursing homes, the primary reason for an EMS call was concern for validity of the DNR order, whereas among adult family homes, the primary concern was appropriate medical authority to declare death., Conclusion: Efforts to clarify existing regulations, streamline the DNR transfer process, and improve communication between EMS and long-term care facilities may result in better fulfillment of residents' end-of-life wishes and a saving of EMS resources.

Background: Little is known about temporal trends in survival and prognostic characteristics of patients with out-of-hospital cardiac arrest treated by emergency medical services (EMS). We hypothesized that an evolving combination of beneficial and adverse factors may contribute to temporal patterns of survival., Methods and Results: We evaluated a population-based cohort of EMS-treated adult patients with cardiac arrest (n=12 591) from 1977 to 2001 in King County, Washington. Time was grouped into an initial 5-year period and 5 successive 4-year periods. We sought to determine the potential impact of temporal changes in prognostic factors typically beyond EMS control termed "fate" factors (for example, patient age) and factors implemented by EMS termed "program" factors (programs of dispatcher-assisted cardiopulmonary resuscitation and basic life support defibrillation). Several characteristics associated with survival changed over time. Observed survival did not change over time among all patients with cardiac arrest (OR=0.98 [0.95, 1.01], trend for each successive time period) and improved over time among patients with witnessed ventricular fibrillation (OR=1.05 [1.01, 1.09]). In models that included all patients with cardiac arrest and controlled for fate factors, advancing time period was associated with an increase in survival (OR=1.08 [1.05, 1.11]). Conversely, in models that controlled for program factors, advancing time period was associated with a decrease in survival (OR=0.95 [0.93, 0.98]). Results were similar among patients with witnessed ventricular fibrillation., Conclusions: The static temporal pattern of survival from cardiac arrest appeared to result from an evolving balance of prognostic factors. Programs implemented by EMS appeared to counter adverse temporal trends in prognostic factors typically beyond EMS control.

Background: The development of congestive heart failure (CHF) in older persons is related to a variety of mechanisms. Hormone replacement therapy (HRT) affects several of the pathways that may be important in the development of CHF. We hypothesized that HRT would be associated with a decreased risk of incident CHF., Methods: Using Cox proportional-hazards regression, we assessed the risk of incident CHF (n = 304) associated with time-dependent past and current use of HRT compared to never use. The Cardiovascular Health Study is a prospective cohort study of community-dwelling adults aged 65 years and older. This analysis included female participants without a history of CHF at baseline (n = 3223)., Results: At baseline, 62% were never users, 26% were past users, and 12% were current users of HRT. Compared with never users, the multivariable relative risk (RR) of CHF was 1.01 (95% confidence interval [95% CI] 0.76,1.34) for past users and 1.34 (0.93,1.94) for current users. Results were similar among most treatment and clinical subgroups, except that the association of current HRT with CHF appeared to depend on body mass index (BMI) or osteoporosis status. The RR was 0.82 (0.43,1.60) for normal weight women, 1.65 (0.95,2.88) for overweight women, and 2.22 (1.06,4.67) for obese women (p = 0.01 for interaction). Similarly, the RR was 0.15 (0.04,0.65) for women with osteoporosis and 1.82 (1.25,2.65) for women without osteoporosis (p = 0.001 for interaction)., Conclusions: Overall, HRT was not associated with the risk of incident CHF, although BMI and osteoporosis appeared to modify the association of HRT with CHF. The risk of CHF was lower in patients with lower BMI or osteoporosis.

Study Objectives: Little is known regarding the potential effects of emergency medical services (EMS) on total heart disease mortality. Although EMS may provide health benefits in less acute cardiac conditions, its immediate, measurable, and direct effect on heart disease mortality is through resuscitation of persons suffering out-of-hospital cardiac arrest. The purpose of this study was to examine the involvement and potential mortality benefit of out-of-hospital EMS care of cardiac arrest on community heart disease mortality., Methods: The investigation was an observational study of all persons with death events resulting from heart disease as defined by heart disease deaths and deaths averted (persons successfully resuscitated from out-of-hospital cardiac arrest by EMS) in a single county from January 1, 2000, through December 31, 2000. The county of study has a population of nearly 2 million people and is composed of urban, suburban, and rural components. State vital records and EMS reports were used to ascertain deaths resulting from heart disease and deaths averted., Results: In the year 2000, 3,577 persons died as a result of heart disease, and 128 persons were successfully resuscitated and discharged from the hospital, for a total of 3,705 death events. EMS responded to 39% (1,428/3,705) of all heart disease death events and 57% (1,428/2,516) of out-of-hospital events, resulting in a 3.5% (128/3,705) reduction in overall heart disease mortality and a 5.1% (128/2,516) reduction in out-of-hospital mortality., Conclusion: EMS was involved in the majority of out-of-hospital heart disease death events, resulting in a measurable reduction in heart disease mortality.

Unlabelled: The interval from collapse to electrical rescue shock is a critical determinant of successful defibrillation in cardiac arrest. In order to achieve the earliest possible defibrillation, many emergency medical services (EMS) systems equip first-responding units with an automated external defibrillator (AED)., Objective: To measure the time from on-scene emergency medical technician (EMT) recognition of cardiac arrest to AED application and shock in ventricular fibrillation (VF) arrest. In addition, the authors sought to understand the reasons for delays., Methods: Using the AED recordings and written EMS reports, the authors conducted a retrospective cohort study of all persons who experienced an EMS-attended VF cardiac arrest in which an AED was applied and a shock delivered by an EMT, from January 1999 through December 2000 (n = 177). Based on the bimodal distribution of times, two groups were assembled: no delay (time to shock < or = 90 seconds) and delayed (time to shock > 90 seconds). Patient and event characteristics associated with delay status were determined using Mantel-Haenszel methods., Results: The median (25th, 75th percentile) time from cardiac arrest recognition to shock was 51 (43, 64) seconds. Ninety-four percent (n = 166) of the cohort received a shock within 90 seconds. Delayed shock was associated with unwitnessed arrest status (odds ratio = 9.3, 95% confidence interval = 2.3, 36.8) and nursing home location (odds ratio = 10.0, 95% confidence interval = 2.1, 47.5)., Conclusion: The findings suggest that a 1-minute goal and a 90-second minimum standard for time to first shock are appropriate for EMT AED defibrillation in the field.

Background: Questions remain about the importance of smoking and smoking cessation after incident myocardial infarction., Objective: To assess the association between smoking status and risk for recurrent coronary events., Design: Retrospective, population-based, inception cohort study., Setting: Health maintenance organization from 1986 to 1996., Patients: 2619 persons who survived to hospital discharge after a first myocardial infarction., Measurements: Relative risk (RR), assessed by using Cox proportional hazards regression analysis, for recurrent coronary events in nonsmokers (persons with no history of smoking), former smokers (persons who had stopped smoking before infarction), quitters (persons who stopped smoking after infarction), and active smokers (persons who continued smoking after infarction)., Results: At the time of incident infarction, 33.6% of patients were nonsmokers, 35.5% were former smokers, and 30.9% were active smokers. Of the 808 persons who were active smokers at the time of incident infarction, 449 quit smoking during hospitalization or after discharge. With nonsmokers as the reference group, the multivariable RR for recurrent coronary events (n = 433) was 1.17 (95% CI, 0.93 to 1.43) for former smokers and 1.51 (CI, 1.10 to 2.07) for active smokers. Among quitters, the RR decreased as duration of cessation increased: With nonsmokers as the reference group, the RR for quitters was 1.62 (CI, 1.02 to 2.61) if the duration of cessation was 0 to less than 6 months, 1.60 (CI, 0.97 to 2.60) if the duration was 6 to less than 18 months, 1.48 (CI, 0.76 to 2.51) if the duration was 18 to less than 36 months, and 1.02 (CI, 0.54 to 1.86) if the duration was 36 months or more (P = 0.01 for trend)., Conclusion: After incident myocardial infarction, smoking was associated with an elevated risk for recurrent coronary events. In persons who quit smoking after infarction, the risk declined to equal that of nonsmokers by 3 years after cessation.

Objective: The emergency department (ED) is ideally reserved for urgent health needs. The ED, however, is often the site of care for nonurgent conditions. The authors investigated whether emergency medical technicians could decrease ED use by patients with nonurgent concerns who use 911 by appropriately identifying and triaging them to alternate care destinations., Methods: From August 2000 through January 2001, two King County fire-based emergency medical services (EMS) agencies participated in an alternate care destination program for patients with specific low-acuity diagnosis codes (intervention group). Eligible patients were offered care at a clinic-based destination as an alternate to the ED (n = 1,016). The frequency of the destination of care (ED, clinic, or home) for the intervention group was compared with a matched control group that was comprised of a preintervention historical cohort of EMS encounters from the same two fire-based agencies and with the same acuity and diagnosis criteria and seasonal interval (n = 2,617)., Results: Compared with the preintervention group, a smaller proportion of patients in the intervention group received care in the ED (44.6% vs. 51.8%, p = 0.001), while a greater proportion of patients in the intervention group received clinic care (8.0% vs. 4.5%, p = 0.001) or home care (no transport) (47.4 vs. 43.7%, p = 0.043). Results were comparable when adjusted for other patient characteristics. Similar relationships were not evident among nonparticipating King County EMS agencies. Based on physician review and patient interview, the alternate care intervention appeared to be safe and satisfactory., Conclusion: An EMS-based program may represent one approach to limiting nonurgent ED use.

Objective: By decreasing the time to defibrillation, automated external defibrillators (AEDs) provide an opportunity for lay people to improve survival in out-of-hospital sudden cardiac arrest. We examined how beliefs, expectations, and actual performance are related to intentions to use an AED during a future heart emergency among a group of seniors., Design and Outcome Measures: One hundred fifty-nine seniors who had been previously trained in the operation of an AED were tested on their AED skills and asked about their perceptions regarding their AED skills; their expectations that an AED would save the life of a cardiac arrest victim; and their intentions to use an AED during a future cardiac event., Results: Logistic regression analyses showed that greater self-perceived ability to use an AED better actual performance on skills assessment but not expectations regarding the efficacy of AED treatment were independently associated with positive intentions to use an AED in a future heart emergency., Conclusions: The likelihood that an elderly lay bystander will actually use an AED during a cardiac event may be closely tied to perceptions of his or her ability to operate an AED.

We determined the presence of IgG and IgM antibody to viral capsid antigen (VCA-IgG, VCA-IgM) and IgG antibody to the Epstein-Barr virus nuclear antigen (EBNA) by indirect immunofluorescence assay (IFA) and enzyme-linked immunosorbent assay (ELISA) during the acute illness and at 1, 2, 6, and 48 months in a prospective population-based case series of 95 persons with an acute illness serologically confirmed as Epstein-Barr virus infection. The acute illness was characterized by the presence of VCA-IgG and VCA-IgM (by ELISA) and by the absence of EBNA in most, but not all, patients. During follow-up, VCA-IgG antibodies remained detectable in all patients, while the proportion with VCA-IgM declined and the number with detectable EBNA antibodies steadily increased. The primary differences between the 2 serologic test methods were the increased persistence of VCA-IgM during follow-up by ELISA and the earlier detection of EBNA by IFA. Clinicians should consider the illness stage and the laboratory technique to appropriately interpret serologic test results in suspected cases of mononucleosis caused by the Epstein-Barr virus.