Development in long-term prognosis of first-time myocardial infarction in relation to use of guideline-recommended treatments: Danish total population cohort study

Background

Evidence from randomized trials during the previous decades have led to several improvements in acute and secondary preventive treatments for myocardial infarction (MI). However, there is a lack of recent knowledge about the implementation of these treatments and how they affected developments in the long-term prognosis of MI.

Purpose

To investigate developments in long-term outcomes after first-time MI and their relation to use of guideline-recommended treatments in a contemporary total population cohort.

Methods

All patients with a first-time MI from 2001 to 2018 were identified through Danish nationwide registries with follow-up through October 6, 2021. The study period was divided into 3-year periods. In each period, the Aalen-Johansen method was used to estimate the absolute 1-year risk for mortality, recurrent MI, heart failure, bleeding hospitalization, and ischemic stroke. The relative frequencies of pharmaceutical treatments and use of coronary procedures were calculated. In each calendar period, the 1-year mortality and recurrent MI risk was standardized to the 2016–2018 distribution of patient characteristics, procedure use, and treatment initiation. Treatment, standardized risks, and recurrent MI risk were evaluated in patients who survived to day 28 post discharge.

Results

In total, 134,884 patients (median age 69 years, 36.5% female) were included and 120,473 survived to day 28 post discharge (median age 68 years, 35.2% female). From 2001–2003 to 2016–2018, the 1-year risks of mortality (23.5% to 12.1%), recurrent MI (6.8% to 3.2%), and ischemic stroke (1.8% to 1.3%) decreased. Risk of heart failure remained relatively stable, whereas the 1-year risk of bleeding hospitalization increased from 2.1% to 3.0%. This pattern remained consistent during very long durations of follow-up (Figure 1). Initiation of statins (58.0% to 86.4%) and adenosine diphosphate receptor inhibitors (42.5% to 85.6%) increased considerably. Use of coronary angiography (37.3% to 84.5%) and percutaneous coronary intervention (24.8% to 63.5%) also increased. There was an attenuated decrease in the standardized 1-year risks of mortality and recurrent MI compared to the observed reference risks: from 8.7% (reference: 11.1%) in 2001–2003 to 6.1% in 2016–2018 for mortality and from 5.6% (reference: 6.8%) in 2001–2003 to 3.1% in 2016–2018 for recurrent MI (Figure 2).

Conclusions

There was a substantial improvement in the long-term risk of mortality and recurrent MI for patients with first-time MI. This improved prognosis was related to an increased use of guideline recommended treatments.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Danish Heart Foundation

Oral fluoroquinolones and risk of aortic dissection and aortic aneurysm: a nationwide nested case-control study

Background

Oral fluoroquinolones are commonly prescribed antibiotics. Observational studies have shown an association between fluoroquinolone-use and subsequent risk of aortic aneurysm (AA) and aortic dissection (AD) due to a potential collagen degrading effect of fluoroquinolones.

Purpose

To investigate if fluoroquinolone-use was associated with increased rates of AA or AD in patients without known aortic disease. Secondly, to investigate if fluoroquinolone-use was associated with increased all-cause mortality and aortic interventions in high-risk patients with known aortic disease.

Methods

We used a nested case-control study design in which individuals aged 30–100 years from 2003 to 2018 were included from Danish nationwide registers. Exclusion criteria were bicuspid aortic valve, coarctation of the aorta, and connective tissue disease. A main cohort and a secondary high-risk cohort were defined. The main cohort comprised patients without history of AA/AD in which two case definitions were used: 1) A broad case definition of first-time AA/AD. 2) A severe case definition of ruptured AA/AD. The high-risk cohort comprised patients surviving index AA/AD admission in which cases were defined as all-cause mortality and aortic interventions.

Cases were matched on age, sex, and year of inclusion in a 1:30 ratio with controls. For the main cohort, a potential dose-response effect was investigated using groups of cumulative defined daily doses (cDDD) of fluoroquinolones. Hazard ratios (HR) with 95% confidence intervals (CI) for fluoroquinolone-use compared with amoxicillin as an active comparator were obtained from time-dependent Cox regression models using multiple exposure windows.

Results

The main cohort comprised 4.81 million individuals with 43,280 cases. Short-term 30-day, intermediate-term 90-day, and long-term 1-year fluoroquinolone use were all not associated with AA/AD (30-day HR 1.18 [95% CI: 0.84 to 1.66]; 90-day HR 1.12 [95% CI 0.96 to 1.30]; 1-year HR 1.00 [95% CI 0.93 to 1.07]). Using a severe case definition of ruptured AA/AD yielded comparable results. For the dose-response analysis, increasing cDDD did not confer increased rates of AA/AD (1–5 cDDD: Reference group; 6–10 cDDD: HR 1.03 [95% CI: 0.87 to 1.23]; >10 cDDD: HR 1.00 [95% CI 0.83 to 1.29]) (Figure 1).

The secondary high-risk cohort included 20,195 patients surviving index admission with 9,183 cases of all-cause mortality and 1,768 cases of aortic interventions. The 30-day HR for all-cause mortality was 1.21 (95% CI 0.92 to 1.60) and the 60-day HR 1.06 (95% CI 0.89 to 1.26). No association with aortic interventions was found either (Figure 2).

Conclusion

Fluroquinolone-use was not associated with AA/AD. Furthermore, fluoroquinolone-use was not associated with all-cause mortality or aortic interventions in potentially susceptible patients with known aortic disease. These findings do not support an increased risk of AA/AD with fluoroquinolone-use.

Funding Acknowledgement

Type of funding sources: None.

Changes in cardiovascular risk factors in patients undergoing first time coronary revascularization from 2003–2020, A nationwide population study

Introduction

Current knowledge of cardiovascular risk factors is primarily based on older studies that may not reflect current populations. Monitoring risk factors may influence decisions about prevention and treatment of ischemic heart disease. We hypothesize that the prevalence of traditional risk factors in patients undergoing first-time coronary revascularization has changed over time.

Purpose

We examined the proportion of patients with traditional cardiovascular risk factors from year 2003–2020 in patients undergoing first-time coronary revascularization.

Methods

We identified all adults undergoing first-time coronary revascularization (percutaneous intervention and bypass grafting) from 2003–2020 using Danish nationwide registries. Risk factors were defined as either medical prescriptions or diagnosis prior to first-time revascularization. We calculated the proportion of individual risk factors per year with associated 95% CI, and calculated the trend using chi-squared test for trend in proportion.

Results

We identified 152,692 patients who underwent first-time coronary revascularization. 78.5% of the patients underwent percutaneous coronary intervention and 21.5% underwent coronary artery bypass grafting, 73.8% were male, mean age 65 (SD 11.5), and 67.9% had at least 1 risk factor at first-time revascularization.

Figure 1 shows the trends in risk factors from 2003 to 2020.

From 2003–2005 to 2018–2020, the proportion of patients with at least 1 risk factors changed from 70.9 to 64.0%, hypertension changed from 41.4 to 36.0%, hypercholesterolemia decreased from 47.6 to 43.6%, aspirin use decreased from 52.4 to 32.06%, diabetes increased from 11.7 to 15.8%, chronic kidney disease increased from 2.4 to 4.4%, and chronic obstructive pulmonary disease increased from 4.95 to 4.96% (p-value for trend <0.001 for all risk factors, except chronic obstructive pulmonary disease (p-value 0.96)).

Conclusion

We assessed the temporal trends in coronary risk factors over a 17-year period in patients undergoing first-time coronary revascularization. We found a large decrease in the proportion of patients with any risk factor, hypertension, hypercholesterolemia, and aspirin use, and an increase in diabetes and chronic kidney disease. The proportion of patients with chronic obstructive pulmonary disease was unchanged.

Funding Acknowledgement

Type of funding sources: None.

Determinants of poor life satisfaction in adolescents with congenital heart disease or early acquired cardiovascular disease: a nationwide observational study

Background

Life expectancy in patients with congenital heart disease (CHD) and patients with early acquired cardiovascular disease (CVD) has increased due to improved treatments during the last decades. As life expectancy increases, focus on long term quality of life and life satisfaction as well as determining focus areas of preventive initiatives becomes essential.

Purpose

To investigate whether poor life satisfaction in adolescents and young adults with CHD or significant CVD is 1) associated with physical and mental challenges and 2) inversely associated with social support and self-efficacy have a protective effect against low life satisfaction.

Methods

Data from a Danish nationwide cross-sectional study was used to identify all patients with either CHD or significant CVD (e.g., arrhythmia, ischemia) aged 15–24 years with at least one contact to a Danish hospital department of cardiology between 2014–2018. Life satisfaction was measured on a scale of 0–10 and dichotomized into good life satisfaction if the score was >6. Using a logistic regression model with interaction terms for sex and adjusted for age and comorbidities, we estimated the association between physical challenges (New York Heart Association classification, NYHA), mental challenges (concentration limitations or memory limitations), social support, self-efficacy, and life satisfaction.

Results

1961 patients were included, 58% had CHD. Median age was 20 years and 50% were female. NYHA-class III or IV were significantly associated with poor life satisfaction (OR: 0.42 [95CI: 0.26; 0.70]) (Figure 1). Likewise, self-reported memory limitations (OR: 0.79 [95CI: 0.68; 0.91]) and concentration difficulty (OR: 0.60 [95CI: 0.51; 0.70]) were associated with poor life satisfaction (Figure 1). In contrast, reported high self-efficacy (OR: 1.67 [95CI: 1.32; 2.12]) and good social support (OR: 2.16 [95CI: 1.60; 2.93]) were both associated with high life satisfaction (Figure 1). Finally, the association between NYHA class III (OR: 0.94 [95CI: 0.34; 2.59]), memory limitations (OR: 0.79 [95CI: 0.58; 1.07]), concentration limitations (OR: 0.71 [95CI: 0.49; 1.04]), and life satisfaction was not significant among individuals with high self-efficacy but remained significant among individuals with good social support.

Conclusions

In adolescents and young adults with CHD or early acquired heart disease, reported physical and mental challenges were associated with reduced self-reported life satisfaction. Both reported high self-efficacy and good social support were associated with increased life satisfaction. High self-efficacy among individuals reduced the negative association between mental or physical challenges and life satisfaction. These findings highlight the need for increased focus on promoting self-efficacy and the need for good social support in adolescents and young adults with functional limitations from their CHD or CVD in order to improve their long-term life satisfaction.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Danish Heart Foundation

Long-term non-cardiovascular morbidity risk remains elevated following myocardial infarction: a nationwide cohort study

Introduction

Risk of cardiovascular events following myocardial infarction (MI) is high, and secondary preventive treatment is largely focused on reducing future cardiovascular risk. As gradual implementation of guideline-based treatments successfully leads to improved survival, long-term non-cardiovascular morbidity is likely of rising importance following MI.

Purpose

To determine the long-term risk of non-cardiovascular morbidity in a contemporary MI population with the aim of informing the need for and scope of prolonged surveillance.

Methods

We included all patients with a first-time MI in Denmark from 2001–2018 matched on age, sex, and date of discharge with up to 4 general population controls. We used the Aalen-Johansen estimator to estimate 1-year and 5-year risk of non-cardiovascular morbidity with death as a competing risk. Non-cardiovascular morbidity was defined as an in-patient hospital admission for any primary cause excluding cardiovascular diagnoses (International classification of diseases, 10th revision codes: I00–99). We also calculated 2-year and 6-year risks of non-cardiovascular morbidity in a stable population of post-MI patients and matched controls, i.e., participants alive with no hospital admissions for 1 full year following study entry. Finally, we estimated 1-year and 5-year risks of cause-specific non-cardiovascular morbidity.

Results

A total of 124,072 patients with MI who survived to hospital discharge were matched with 496,277 general population controls. Median age was 68 years and 35.5% were female. The 1-year and 5-year risk of non-cardiovascular morbidity was elevated for patients with MI compared to controls: 38.6% (95% confidence interval: 38.3–38.9) vs 15.3% (15.2–15.4) and 64.8% (64.6–65.1) vs 45.8% (45.7–45.9), respectively (Figure 1). Regarding cause-specific morbidity, risks of respiratory disease, gastrointestinal disease, and infectious disease particularly were high (Figure 2). For example, 1-year risk of infection was 4.5% for patients with MI and 1.8% for controls and 5-year risk of respiratory disease was 16.3% for patients with MI and 9.7% for controls. Furthermore, in the stable population (patients with MI, n=50,144; controls, n=159,467, median age 64 years, 33.0% female), risk of non-cardiovascular morbidity remained elevated at 2 years (17.2% [16.8–17.5] vs 11.3% [11.1–11.5]) and 6 years (49.2% [48.7–49.7] vs 39.8% [39.6–40.1]) post MI (Figure 1).

Conclusions

Risk of non-cardiovascular morbidity was high in patients following myocardial infarction, particularly for respiratory disease, gastrointestinal disease, and infectious disease. The risk remained elevated during long-term follow up. The study highlights the importance of additional focus on non-CV morbidity to further improve outcomes.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Danish Heart Foundation

Readmission after transcatheter aortic valve implantation according to frailty

Background

Readmissions and time spent hospitalized following transcatheter aortic valve implantation (TAVI) are important parameters of patient autonomy, particularly for frail patients with limited life-expectancy. Yet, such data remain scarce.

Purpose

To investigate actual time spent hospitalized the first year after TAVI. Secondly, to investigate time spent hospitalized according to frailty risk.

Methods

Through Danish, nationwide registries, we included all patients undergoing TAVI and alive at discharge between January 2008 and June 2020. From discharge, patients were followed until death, emigration, end of study period, or one year of follow-up, whichever came first. During follow-up, all in-patient hospital admissions were identified according to ICD-10 diagnosis codes. Length of stay was calculated, and cumulative numbers of days hospitalized was presented. Further, the proportion of patients dying within one year of follow-up was calculated.

Using The Hospital Frailty Risk Score, a validated frailty risk assessment tool, patients were categorized as low, intermediate, and high frailty risk. We then evaluated the time spent hospitalized stratified by frailty risk group.

Results

The study population comprised 5,464 patients undergoing first-time TAVI with a median age of 81 years among whom 55.2% were males. After one year, 445 (8.1%) patients had died. In total, 2,452 (44.9%) of TAVI patients survived one year and were never admitted, whereas 3,012 (55.1%) patients were admitted at least once or died within one year of TAVI. Of these, 1,200 (21.9%) patients were admitted for more than two weeks or died within one year of TAVI (Figure 1).

Regarding frailty, 3,296 (60.3%), 1,965 (36.0%), and 203 (3.7%) patients were classified as low, intermediate, and high frailty risk, respectively. In the low frailty risk group, 6.2% of patients died within one year and 50.4% survived one year without a hospital admission. By contrast, 16.7% of patients in the high frailty risk group died within one year and only 24.6% survived one year without a hospital admission. Further, 17.1% of patients in the low frailty risk group were admitted for more than two weeks or died within one year of TAVI compared with 47.3% in the high frailty risk group (Figure 2).

Conclusion

Readmissions in the first year after transcatheter aortic valve implantation were common and time spent hospitalized after transcatheter aortic valve implantation was significant. Our results were clearly related to frailty, which should be considered for future prevention strategies.

Funding Acknowledgement

Type of funding sources: None.

5225Bystander cardiopulmonary resuscitation and survival in out-of-hospital cardiac arrest of non-cardiac origin

Background

Knowledge about the effect of bystander cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OHCA) of non-cardiac origin is lacking. We aimed to investigate the association between bystander CPR and survival in OHCA of presumed non-cardiac origin.

Methods

From the Danish Cardiac Arrest Registry and through linkage with national Danish healthcare registries we identified all adult patients with OHCA of presumed non-cardiac origin in Denmark (2001–2014). These were categorized further into OHCA of medical and non-medical cause. We analyzed temporal trends in bystander CPR and 30-day survival during the study period. Multiple logistic regression was used to examine the association between bystander CPR and 30-day survival and reported as standardized 30-day survival chances with versus without bystander CPR standardized to the prehospital OHCA-factors and patient characteristics of all patients in the study population.

Results

We identified 10,761 OHCAs of presumed non-cardiac origin. Bystander CPR was associated with an increased 30-day survival chance of 3.4% (95% confidence interval [CI]: 2.9–3.9) versus 1.8% (95% CI: 1.4–2.2) with no bystander CPR, corresponding to a significant difference of 1.6% (95% CI: 0.9–2.3). During the study period, the overall bystander CPR rates increased from 13.6% (95% CI: 11.2–16.5) to 62.7% (95% CI: 60.2–65.2). 30-day survival increased overall from 1.3% (95% CI: 0.7–2.6) to 4.0% (95% CI: 3.1–5.2). Similar findings were observed in subgroups of medical and non-medical OHCA.

Table 1. Patient and arrest characteristics according to cause of out-of-hospital cardiac arrest Overall Medical OHCA Non-medical OHCA Patient characteristics   Total patients 10761 7625 3136   Median age,y 67 70 50   Male, n (%) 6357 (59.1) 4154 (54.5) 2204 (70.4) OHCA factors   Witnessed arrest, n (%) 4306 (40.0) 3574 (46.9) 732 (23.3)   Public location, n (%) 6979 (64.9) 5494 (72.1) 1485 (47.4) OHCA, out-of-hospital cardiac arrest; CPR, cardiopulmonary resuscitation.

Figure 1. Temporal trends

Conclusion

Bystander CPR was associated with a higher chance of 30-day survival among OHCA of presumed non-cardiac origin regardless of the underlying cause (medical/non-medical). Rates of bystander CPR and 30-day survival improved during the study period.

2285Increased risk of out-of-hospital cardiac arrest associated with psychiatric disorders

Introduction

Patients with psychiatric disorders are at high risk of cardiovascular morbidity and mortality; yet, the risk of out-of-hospital cardiac arrest (OHCA) compared to the general population remains unknown.

Purpose

We investigated whether the presence and severity of different psychiatric disorders were associated with a higher risk of OHCA.

Methods

We conducted a case-control study matching all adult patients with OHCA of presumed cardiac cause between 2001 and 2014 with up to nine controls from the entire Danish population on age, sex and ischemic heart disease (IHD). Patients with psychiatric disorders were identified using in- and out-patient hospital diagnoses – both primary and secondary - before index date. We identified six mutually exclusive psychiatric disorders that were separately examined: personality disorders, anxiety, substance-related mental disorders, depression, bipolar disorder and schizophrenia. The risk of OHCA associated with the six psychiatric disorders was evaluated by conditional logistic regression adjusting for comorbidities, concomitant pharmacotherapy, socioeconomic status and marital status.

Results

We included 32,447 OHCA cases matched with 291,999 controls from the general population. Overall, the median age was 72 years, 67% were male and 29% had IHD prior to index date. All the six psychiatric disorders examined were more common among cases than controls; depression was the most common psychiatric disorders in both groups: 5.0% among cases and 2.8% among controls. Concurrently, all six psychiatric disorders were associated with significantly higher odds of OHCA: personality disorders (odds ratio (OR) 1.30 [95% confidence interval (CI) 1.06–1.60], anxiety OR 1.26 [95% CI 1.15–1.39], substance induced-mental disorders OR 2.36 [95% CI 2.17–2.57], depression OR 1.27 [95% CI 1.19–1.35], bipolar disorder OR 1.32 [95% CI 1.16–1.50] and schizophrenia OR 1.80 [95% CI 1.58–2.05] (Figure). The association persisted unaffected when we studied psychiatric patients neither exposed to antipsychotics nor to antidepressants. We observed a trend towards a stronger association when we stratified according to the severity of the psychiatric disorder (Figure). Severe disorders where classified as at least one hospitalization for the specific psychiatric illness as primary diagnosis during the five years prior to index date.

Conclusions

Common psychiatric disorders including personality disorders, anxiety, substance-related mental disorders, depression, bipolar disorder and schizophrenia are significantly associated with higher odds of OHCA. These findings provide a rationale for early cardiovascular risk factor screening and, potentially, management among psychiatric patients to identify patients at high risk of OHCA.

Acknowledgement/Funding

ESCAPE-NET project

P2548Lithium use and risk of out-of-hospital cardiac arrest in patients with bipolar disorder: A nationwide nested case-control study

Background

Lithium is a mood stabilizer widely used in the treatment of bipolar disorder. Lithium has been linked to malignant proarrhythmic electrocardiographic changes such as QT-prolongation, atrioventricular and sinoatrial block. However, evidence regarding the risk of cardiac arrest with lithium use is lacking.

Purpose

We investigated the risk of out-of-hospital cardiac arrest associated with lithium use among patients with bipolar disorder.

Methods

All out-of-hospital cardiac arrest cases from 2001 through 2014 of presumed cardiac cause with a history of bipolar disorder were identified from the nationwide Danish Cardiac Arrest Registry. We conducted a nested case-control study by matching all cardiac arrest cases with bipolar disorder on age, sex and time since first diagnosis of bipolar disorder with four controls from the general population who also had a history of bipolar disorder. Conditional logistic regression adjusted for comorbidities and concomitant pharmacotherapy was used to determine the association between lithium monotherapy and risk of out-of-hospital cardiac arrest compared to mood stabilizing monotherapy with valproate, lamotrigine and quetiapine, respectively. Exposure was defined as redeemed prescriptions for only one of either lithium, valproate, lamotrigine or quetiapine up to two months before index.

Results

The study population consisted of 1,410 patients with bipolar disorder, comprising 282 out-of-hospital cardiac arrest cases each matched with 4 controls. The median age was 69 years, 47.2% were male and the median time from first diagnosis of bipolar disorder was 7.25 years. Among cases, 59 (20.9%) were in lithium monotherapy and among controls the number was 299 (26.5%). For monotherapy with other mood stabilizers we observed the following distributions: quetiapine 18 (6.4%) cases and 51 (4.5%) controls, valproate 12 (4.3%) cases and 51 (4.5%) controls, and lamotrigine 15 (5.3%) cases and 64 (5.7%) controls. Lithium was not associated with an increased risk of OHCA compared to other mood stabilizing drugs: Hazard ratio (HR) 0.64 [95% confidence interval (CI) 0.31–1.33] (reference quetiapine), HR 0.56 [95% CI 0.25–1.24] (reference valproate) and HR 0.53 [95% CI 0.25–1.10] (reference lamotrigine).

Figure 1

Conclusion

Among patients with bipolar disorder, lithium was not associated with an increased risk of cardiac arrest compared to other mood stabilizing drugs. Further studies focusing on the cardiovascular safety of mood stabilizing drugs are warranted.

Bystander cardiopulmonary resuscitation and survival in patients with out-of-hospital cardiac arrest of non-cardiac origin

BACKGROUND

Knowledge about the effect of bystander cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OHCA) of non-cardiac origin is lacking. We aimed to investigate the association between bystander CPR and survival in OHCA of presumed non-cardiac origin.

METHODS

From the Danish Cardiac Arrest Registry and through linkage with national Danish healthcare registries we identified all patients with OHCA of presumed non-cardiac origin in Denmark (2001-2014). These were categorized further into OHCA of medical and non-medical cause. We analyzed temporal trends in bystander CPR and 30-day survival during the study period. Multiple logistic regression was used to examine the association between bystander CPR and 30-day survival and reported as standardized 30-day survival chances with versus without bystander CPR standardized to the prehospital OHCA-factors and patient characteristics of all patients in the study population.

RESULTS

We identified 10,761 OHCAs of presumed non-cardiac origin. Bystander CPR was associated with a significantly higher 30-day survival chance of 3.4% (95% confidence interval [CI]: 2.9-3.9) versus 1.8% (95% CI: 1.4-2.2) without bystander CPR. A similar association was found in subgroups of both medical and non-medical OHCA. During the study period, the overall bystander CPR rates increased from 13.6% (95% CI: 11.2-16.5) to 62.7% (95% CI: 60.2-65.2). 30-day survival increased overall from 1.3% (95% CI: 0.7-2.6) to 4.0% (95% CI: 3.1-5.2).

CONCLUSION

Bystander CPR was associated with a higher chance of 30-day survival among OHCA of presumed non-cardiac origin regardless of the underlying cause (medical/non-medical). Rates of bystander CPR and 30-day survival improved during the study period.

Case Report: Industrial X-Ray Injury Treated With Non-Cultured Autologous Adipose-Derived Stromal Vascular Fraction (SVF)

Local cutaneous injuries induced by ionizing radiation (IR) are difficult to treat. Many have reported local injection of adipose-derived stromal vascular fraction (SVF), often with additional therapies, as an effective treatment of IR-induced injury even after other local therapies have failed. The authors report a case of a locally recurrent, IR-induced wound that was treated with autologous, non-cultured SVF without other concurrent therapy. A nondestructive testing technician was exposed to 130 kVp x rays to his non-dominant right thumb on 5 October 2011. The wound healed 4 mo after initial conservative therapy with oral/topical α-tocopherol, oral pentoxifylline, naproxen sodium, low-dose oral steroids, topical steroids, hyperbaric oxygen therapy (HBOT), oral antihistamines, and topical aloe vera. Remission lasted approximately 17 mo with one minor relapse in July 2012 after minimal trauma and subsequent healing. Aggressive wound breakdown during June 2013 required additional therapy with HBOT. An erythematous, annular papule developed over the following 12 mo (during which time the patient was not undergoing prescribed treatment). Electron paramagnetic resonance (EPR) done more than 2 mo after exposure to IR revealed dose estimates of 14 ± 3 Gy and 19 ± 6 Gy from two centers using different EPR techniques. The patient underwent debridement of the 0.5 cm papular area, followed by SVF injection into and around the wound bed and throughout the thumb without complication. Eleven months post SVF injection, the patient has been essentially asymptomatic with an intact integument. These results raise the possibility of prolonged benefit from SVF therapy without the use of cytokines. Since there is currently no consensus on the use of isolated SVF therapy in chronic, local IR-induced injury, assessment of this approach in an appropriately powered, controlled trial in experimental animals with local radiation injury appears to be indicated.

The Internet's role in a biodosimetric response to a radiation mass casualty event

Response to a large-scale radiological incident could require timely medical interventions to minimize radiation casualties. Proper medical care requires knowing the victim's radiation dose. When physical dosimetry is absent, radiation-specific chromosome aberration analysis can serve to estimate the absorbed dose in order to assist physicians in the medical management of radiation injuries. A mock exercise scenario was presented to six participating biodosimetry laboratories as one individual acutely exposed to Co under conditions suggesting whole-body exposure. The individual was not wearing a dosimeter and within 2-3 h of the incident began vomiting. The individual also had other medical symptoms indicating likelihood of a significant dose. Physicians managing the patient requested a dose estimate in order to develop a treatment plan. Participating laboratories in North and South America, Europe, and Asia were asked to evaluate more than 800 electronic images of metaphase cells from the patient to determine the dicentric yield and calculate a dose estimate with 95% confidence limits. All participants were blind to the physical dose until after submitting their estimates based on the dicentric chromosome assay (DCA). The exercise was successful since the mean biological dose estimate was 1.89 Gy whereas the actual physical dose was 2 Gy. This is well within the requirements for guidance of medical management. The exercise demonstrated that the most labor-intensive step in the entire process (visual evaluation of images) can be accelerated by taking advantage of world-wide expertise available on the Internet.

Dose coefficients for intakes of radionuclides via contaminated wounds

The NCRP Wound Model, which describes the retention of selected radionuclides at the site of a contaminated wound and their uptake into the transfer compartment, has been combined with the ICRP element-specific systemic models for those radionuclides to derive dose coefficients for intakes via contaminated wounds. These coefficients can be used to generate derived regulatory guidance (i.e., the activity in a wound that would result in an effective dose of 20 or 50 mSv, or in some cases, a organ-equivalent dose of 500 mSv) and clinical decision guidance (i.e., activity levels that would indicate the need for consideration of medical intervention to remove activity from the wound site, administration of decorporation therapy or both). Data are provided for 38 radionuclides commonly encountered in various activities such as nuclear weapons, fuel fabrication or recycling, waste disposal, medicine, research, and nuclear power. These include 3H, 14C, 32P, 35S, 59Fe, 57,58,60Co, 85,89,90Sr, 99mTc, 106Ru, 125,129,131I, 134,137Cs, 192Ir, 201Tl, 210Po, 226,228Ra, 228,230,232Th, 234,235,238U, 237Np, 238,239,240,241Pu, 241Am, 242,244Cm, and 252Cf.

Medical management of radiation injuries: current approaches

The current approach to medical management of irradiated patients begins with early diagnosis of radiation injury. Medical assessment of radiation dose is based on event history, symptomatology and laboratory results, with emphasis on time to emesis and lymphocyte depletion kinetics. Dose assessment provides a basis for early use of haematopoietic growth factors that can shorten the period of neutropaenia for patients with acute radiation syndrome. Assessments of haematopoietic, gastrointestinal and cutaneous syndromes have improved in recent years, but treatment options remain limited. Selected examples of current developments are presented.

The ventricular assist device: An overview

With the continued shortage of available donor organs, the need for a mechanical alternative to support increasing numbers of heart failure patients has become increasingly apparent. This article reviews the ventricular assist devices currently approved by the Food and Drug Administration, and some of the concepts surrounding ventricular assist device therapy. Common postoperative and long-term concerns are addressed, and nursing care of these complicated patients is reviewed.

What is 'heavy'?

One of the work practices frequently taught to employees is to estimate the heaviness of load before it is actually handled. If it is 'heavy', then one should ask for help. However, limited information can be found in the ergonomics literature about what a person perceives as a 'heavy load'. This study was conducted on 20 male and 20 female workers in the package delivery industry to estimate the amounts of load that correspond to various levels of load heaviness (e.g. 'somewhat heavy'). Experienced employees were used for this purpose. The distribution of loads within each heaviness level was developed using fuzzy sets theory. The maximum load (i.e. 23 kg) defined by the US National Institute for Occupational Safety and Health represents a 'somewhat heavy' load based on the analysis of load distribution (corresponding to a 1.0 certainty factor). Also, the 40 kg considered in the 1981 NIOSH guidelines may be classified as a 'very heavy' load. A comparative analysis of the results of this study with norms established in prior research indicates that one should be more careful in the interpretation of statistical norms for human perception of load handling. A 'moderate' level of load heaviness (i.e. 14 kg) can be handled by 85% of the worker population.

Possible functional linkage between the cardiac dihydropyridine and ryanodine receptor: acceleration of rest decay by Bay K 8644

The effect of the dihydropyridine L-Type Ca chanel agonist Bay K 8644 on post-rest contractions in ferret ventricular muscle and isolated myocytes was investigated. Bay K 8644 was shown to abolish rest potentiation and greatly accelerate rest decay. The post-rest contraction suppressed by Bay K 8644 was accompanied by action potentials of large amplitude and longer duration, but voltage-clamp measurements showed that this suppression was not due to a supra-optimal ICa trigger. Caffeine-induced contractures and rapid cooling contractures demonstrated an accelerated rest-dependent decline in sarcoplasmic reticulum (SR) Ca content in the presence of Bay K 8644, which was present even with Ca-free superfusion during rest. Thus, the Bay K 8644-induced decline of SR Ca during rest was independent of extracellular Ca or ICa. To explore whether the binding of Bay K 8644 to the dihydropyridine receptor could alter the SR Ca release channel/ryanodine receptor in a more direct way, ryanodine binding was measured in the absence and presence of Bay K 8644. Ryanodine binding to isolated ferret ventricular myocytes was increased by Bay K 8644 under conditions where sarcolemmal-SR junctions might be expected to be intact, but not after physical disruption. These results are consistent with a working hypothesis where Bay K 8644 may bind to the dihydropyridine receptor and this may lead to physical changes in the linkage between the dihydropridine receptor and a subset of ryanodine receptors, thereby increasing the opening of the SR Ca release channel during rest (and accelerating resting Ca loss).

Can back supports relieve the load on the lumbar spine for employees engaged in industrial operations?

In recent years, there has been an increased use of back supports in US industry to reduce the frequency and concomitant costs of lower-back disorders. The obvious question is, 'Can back supports relieve the load on the lumbar spine for employees engaged in industrial operations?'. This paper is directed towards answering this question because there have been mixed conclusions in the literature reporting on the efficacy of back supports. The literature concerning the biomechanical, physiological and psychophysical effects of back supports on the human spine has been reviewed as well as the use of back supports to control injury in the workplace. A critical assessment of the findings reported by various investigators has been made together with a discussion of the mechanisms used by the trunk muscles to provide extrinsic stability to the spine. It is hypothesized that the extrinsic stability of the spine is manifested through more than one mechanism. These mechanisms may act simultaneously or sequentially to stabilize the trunk. Finally, the ergonomics of back supports as a corporate policy are discussed.

R-PEP-27, a potent renin inhibitor, decreases plasma angiotensin II and blood pressure in normal volunteers

The hemodynamic and humoral effects of the specific human renin inhibitor R-PEP-27 were studied in six normal human subjects on low and high sodium intake diets. An intravenous infusion of R-PEP-27 (0.5 to 16 micrograms/min/kg body wt) reduced blood pressure in a dose-dependent fashion; the mean arterial blood pressure at the end of the infusion fell from 128 +/- 4/83 +/- 4 to 119 +/- 3/71 +/- 3 mm Hg (mean +/- SEM) (P < .01) during the low sodium intake diet. R-PEP-27 had no effect on blood pressure during the high sodium intake diet. R-PEP-27 significantly reduced plasma angiotensin II and aldosterone concentrations. The temporal response to R-PEP-27 suggests that it is a short-lived although highly potent competitive inhibitor of renin; this peptide is a valuable and specific physiologic probe of the renin-angiotensin system.

Comparison of the cardiac and hemodynamic effects of lisinopril and atenolol in patients with hypertension: therapeutic implications

The antihypertensive and hemodynamic effects of lisinopril and atenolol were evaluated in 21 patients with mild-to-moderate essential hypertension. Left ventricular systolic and diastolic performances were assessed prior to and following treatment by first-pass radionuclide cineangiography at rest and during peak upright bicycle exercise. Both lisinopril and atenolol treatment significantly reduced the blood pressure. Lisinopril therapy was associated with a reduction in systemic vascular resistance and left ventricular end-diastolic and end-systolic volumes but no change in stroke volume, cardiac output, peak ejection rate, peak filling rate, time to peak ejection rate, or time to peak filling rate. In contrast, atenolol therapy was associated with an increase in end-diastolic volume and stroke volume but no change in cardiac output; the left ventricular peak ejection and peak filling rates were decreased by atenolol treatment. Although both lisinopril and atenolol each significantly reduced the blood pressure, lisinopril had no effect on left ventricular systolic or diastolic performance; in contrast, atenolol decreased both systolic and diastolic parameters of ventricular performance. Left ventricular function may be affected in significantly different ways despite apparent similarities in blood pressure control in patients who respond to angiotensin converting enzyme inhibition or beta-adrenergic receptor blockade. Differences in hemodynamic response to an antihypertensive agent may be important in the selection of a drug for the treatment of subsets of patients with cardiac function abnormalities.

Effects of antianginal therapy on left ventricular systolic and diastolic performance: comparison of the response to bepridil, propranolol, and diltiazem

Abnormalities of left ventricular (LV) systolic performance develop during exercise in patients with coronary artery disease (CAD) as a result of ischemia-induced regional wall motion abnormalities. Like patients with hypertension and those with hypertrophic cardiomyopathy, patients with CAD display abnormalities of LV diastolic performance under basal conditions in the absence of ischemia. The purpose of these studies was to compare the effects of bepridil versus those of propranolol or diltiazem in patients with exertional angina pectoris. LV systolic and diastolic performance were assessed at rest and during peak upright bicycle exercise by first-pass radionuclide ventriculography. Compared with propranolol, bepridil increased exercise capacity, cardiac output, and stroke volume and decreased systemic vascular resistance. Compared with diltiazem, bepridil increased exercise capacity, peak filling rate, and early diastolic filling fraction and decreased systemic vascular resistance, heart rate, time to peak filling rate, and atrial filling volume. Bepridil therapy is associated with improved exercise capacity and decreased anginal frequency and nitroglycerin consumption. In addition, its use is accompanied by favorable changes in LV systolic and diastolic function at rest and during exercise. These changes are consistent with benefits resulting from resolution of myocardial ischemia as well as from positive lusitropic effects of bepridil on the ventricular myocardium.

Effects of fosinopril on cardiac function in patients with hypertension. Radionuclide assessment of left ventricular systolic and diastolic performance

Numerous pharmacologic agents are capable of lowering the blood pressure of hypertensive patients; however, each drug has a characteristic side effect profile and effect on cardiac performance. In this study, the hemodynamic effects of the angiotensin converting enzyme inhibitor fosinopril were assessed at rest and at peak upright bicycle exercise by first-pass radionuclide cineangiography in 12 patients with essential hypertension. Fosinopril reduced blood pressure at rest in the seated position from 152/101 to 131/85 mm Hg (P less than .01) and at peak exercise from 206/103 to 184/91 mm Hg (P less than .01). Fosinopril therapy was associated with an increase in stroke volume and cardiac output and a decrease in systemic vascular resistance at rest and during peak exercise. Both peak ejection rate and peak filling rate increased significantly at rest during fosinopril therapy. The unique cardiotropic response to fosinopril may reflect its effects on the myocardial renin-angiotensin system, and suggests that this agent may offer a therapeutic advantage compared with other angiotensin converting enzyme inhibitors.

Nifedipine improves left ventricular function in patients with hypertension

The effects of the nifedipine gastrointestinal therapeutic system (GITS) on blood pressure (BP), systemic vascular resistance (SVR), and left ventricular (LV) performance were determined in eight patients with essential hypertension. LV systolic and diastolic performance were assessed by first-pass radionuclide cineangiography at rest and during upright bicycle exercise after initial and long-term BP reduction. After initial treatment, end-diastolic volume (LVEDV) increased in association with an increase in stroke volume (SV), cardiac output (CO), and peak ejection rate. After long-term treatment, LVEDV decreased, SV and CO returned to pretreatment values, early diastolic filling fraction increased, and time to peak filling rate decreased. These hemodynamic changes are consistent with an initial predominant effect of vasodilation on LV function. With long-term treatment, the effects on LV diastolic performance are consistent with a positive lusitropic effect of nifedipine GITS. Nifedipine GITS is an effective agent for control of hypertension; its hemodynamic effects are consistent with both an effect on SVR due to decreased vascular smooth muscle contraction and a direct lusitropic effect on myocardial function.

Functional interconversion of rest decay and ryanodine effects in rabbit and rat ventricle depends on Na/Ca exchange

Rapid cooling contractures were used to assess changes in sarcoplasmic reticulum (SR) Ca content in isolated rabbit and rat ventricular muscle during rest, with altered transsarcolemmal [Na] and [Ca] gradients and in the presence and absence of 100 nM ryanodine. In rabbit there is normally a rest-duration dependent decline in SR Ca content (rest decay), whereas in rat there is a short-term increase in SR Ca content (rest potentiation) and little evidence of rest decay. Ryanodine greatly accelerates the rate of rest decay in rabbit, depleting the SR of Ca in approximately 1 s, whereas in rat, ryanodine does not appear to drain the SR even after a 10 min rest. Elevation of intracellular Na activity in rabbit (by Na-pump inhibition) to a level similar to that measured in control rat during rest (Shattock and Bers, Am. F. Physiol., 256: C813-C822, 1989) makes rest-dependent changes of SR Ca content in these two tissues similar. The rest decay in rabbit in the presence of ryanodine is also markedly slowed after Na-pump inhibition. In rat, reduction of [Ca]0 allows rest decay to occur (+/- ryanodine), but this rest decay can be largely prevented by simultaneous reduction of [Na]o (to maintain [Na]3/[ Ca] constant) which serves to keep the thermodynamic driving force on a 3:1 Na/Ca exchange constant. We conclude that the process of rest decay and rest potentiation in both rabbit and rat ventricle depends on the sarcolemmal Na/Ca exchange. Furthermore, these species can be functionally interconverted by manipulation of the [Na] and [Ca] gradients. The ability of ryanodine to deplete the SR of Ca also depends critically on other transport systems (particularly Na/Ca exchange) to remove Ca from the cytoplasm.

Nifedipine, but not propranolol, improves left ventricular systolic and diastolic function in patients with hypertension

The effects of nifedipine and propranolol on cardiac function both at rest and at peak exercise were compared in 22 hypertensive patients whose diastolic blood pressures remained in excess of 95 mm Hg despite diuretic therapy. In this double-blind, placebo-controlled study, left ventricular systolic and diastolic function at rest and at peak exercise during bicycle ergometry was assessed by first-pass radionuclide angiography using the Baird Scinticor before and after treatment with either nifedipine or propranolol. Both agents effectively reduced blood pressure in the supine and upright positions and at peak exercise. Nifedipine was associated with a significant increase in cardiac output and stroke volume at rest and at peak exercise, while propranolol decreased cardiac output at rest and at peak exercise. Systemic vascular resistance decreased with nifedipine treatment at rest and at peak exercise, but increased significantly with propranolol. Nifedipine increased ejection fraction in patients at rest and also increased maximal oxygen consumption at peak exercise, while propranolol decreased maximal oxygen consumption at peak exercise. At rest and at peak exercise, nifedipine increased peak filling rate, but time to peak filling rate was not affected by either drug. The fraction of total diastolic filling at the midpoint of diastole was significantly increased by nifedipine therapy at rest but was not affected by propranolol therapy. Nifedipine significantly decreased atrial filling volume while propranolol had no effect. Propranolol therapy did not result in any improvement in left ventricular function. In contrast, nifedipine improved left ventricular systolic and diastolic function at rest and peak exercise. Future selection of an antihypertensive agent should include consideration of the impact of therapy on left ventricular function.

Can Ca entry via Na-Ca exchange directly activate cardiac muscle contraction?

Developed twitch tension and action potentials were recorded in rabbit ventricular muscle in physiological saline at 30 degrees C stimulated at 0.5 Hz. Addition of 5 microM nifedipine to block Ca entry via Ca channels almost abolished twitches (to 2.5 +/- 0.7%, S.E.M., n = 10 of control). This suggests that under normal conditions Ca entry via Na-Ca exchange is insufficient to activate contractions. However, when muscles are first exposed to 4 microM acetylstrophanthidin to elevate [Na]i the same exposure to nifedipine only partially suppresses twitches (to 59 +/- 12% of the original control). This suggests that when [Na]i is elevated, Ca entry via the Na-Ca exchange may be adequate to partially activate contraction. From this result it is not clear whether Ca entry via Na-Ca exchange is sufficient to activate contraction directly or whether sarcoplasmic reticulum (SR) Ca release is required. When these experiments were carried out in the presence of 5 to 10 mM caffeine or 100 nM ryanodine similar results were obtained. That is, nifedipine still abolished contractions in the presence of caffeine or ryanodine (to 3.8 +/- 0.3% and 1.3 +/- 0.4%, respectively), but only partially inhibited contractions in the presence of caffeine + acetylstrophanthidin (to 21 +/- 5%) or ryanodine + acetylstrophanthidin (10 +/- 2%). Thus, it appears that even in the absence of a functional SR and with Ca current blocked, Na-Ca exchange might bring sufficient Ca into the cell to activate appreciable contractions, but only when [Na]i is elevated. Action potential duration is decreased by nifedipine and acetylstrophanthidin and is further decreased when nifedipine is added on top of acetylstrophanthidin. If this Ca entry is by an electrogenic 3 Na: 1 Ca exchange, Ca entry will be favored at more positive membrane potentials. If the action potential were not so abbreviated with these drugs, Na-Ca exchange might bring in more Ca and activate additional tension.

Evaluation of bepridil for the treatment of angina pectoris: evidence for preservation of left ventricular function

The efficacy of bepridil (400 mg once a day) was assessed in 15 patients with exertional angina pectoris. All 15 patients reported substantial clinical improvement during bepridil treatment compared with placebo treatment. Episodes of angina were 11.8 +/- 4.1 (mean +/- standard error of the mean)/week with placebo and 3.8 +/- 1.6 with bepridil (p less than 0.05); nitroglycerin use was 9.1 +/- 3.3 tablets/week with placebo and 3.5 +/- 1.7 with bepridil (p less than 0.05). Five of 15 patients receiving bepridil did not experience angina during treadmill exercise; in the remaining 10 patients, time to onset of angina during exercise was 5.7 +/- 0.9 minutes with bepridil as opposed to 4.5 +/- 0.8 minutes with placebo (p less than 0.05). Left ventricular (LV) performance at peak exercise as measured by first-pass radionuclide angiography revealed the ejection fraction to be 38 +/- 3% during placebo therapy and 47 +/- 4% during bepridil therapy (p less than 0.0025). End-diastolic LV volume was unchanged, but end-systolic volume was 136 +/- 11 and 117 +/- 13 ml (p less than 0.05) and stroke volume was 82 +/- 6 and 97 +/- 9 ml (p less than 0.05) during placebo and bepridil therapy, respectively. Heart rate at peak exercise was 136 +/- 3 beats/min with placebo and 128 +/- 3 beats/min with bepridil; however, blood pressure was unchanged. These studies demonstrate that bepridil results in significant clinical improvement and enhanced LV performance in patients with angina pectoris.