Clinical Characteristics, Incidences, and Mortality Rates for Type A and B Aortic Dissections: A Nationwide Danish Population-Based Cohort Study From 1996 to 2016.

BACKGROUND: Population-based epidemiologic studies of aortic dissections (ADs) are needed. This study aimed to report clinical characteristics, incidences, and mortality rates for adult patients admitted to Danish hospitals with type A AD (TAAD) or type B AD (TBAD) from 1996 through 2016. METHODS: We conducted a nationwide, population-based register study. All cases of AD registered with International Classification of Diseases, Tenth Revision codes in the Danish National Patient Registry at time of admission to a hospital with available medical records underwent validation. Data were merged between nationwide health registries including the cause of death registry. Patients with validated AD were matched 1:10 on sex and age with patients with hypertension from the general Danish population. RESULTS: Of 5018 registered cases of AD, 4183 cases underwent review and 3023 (60.2%) were validated as AD. After exclusions, the distribution of validated TAAD and TBAD was 1620 (60.5%) and 1059 (39.5%; P<0.001), 67.5% and 67.0% of patients were men, and mean ages at dissection were 63.5±12.9 and 67.5±12.2 years (P<0.001), respectively. The most prevalent comorbidities for TAAD were hypertension (55.2%), thoracic aortic aneurysms (14.6%), and chronic obstructive pulmonary disease (13.1%); for TBAD, the most prevalent comorbidities were hypertension (64.1%), aortic aneurysms at any location (7.5% to 12.0%), and chronic obstructive pulmonary disease (15.7%). The overall mean annual incidence rate was 4.2/100 000 patient-years. Incidence was significantly higher for TAAD (2.2/100 000) compared with TBAD (1.5/100 000; P<0.001). The 30-day mortality rates for validated TAAD and TBAD were 22.0% and 13.9% (P<0.001), respectively, with no significant changes over time or between sexes. Adjusted 5-year overall mortality rates for TAAD and TBAD were hazard ratio 3.2 (2.9 to 3.5; P<0.001; aortic-related cause of death, 57.0%) and hazard ratio 2.1 (1.9 to 2.4; P<0.001; aortic-related cause of death, 42.8%), respectively, compared with the general hypertensive population. Among patients who survived 30 days from dissection, the adjusted 5-year overall mortality rates were hazard ratio 1.1 (1.0 to 1.3; P=0.12; aortic-related cause of death, 23.2%) and hazard ratio 1.4 (1.2 to 1.6; P<0.001; aortic-related cause of death, 25.6%) for TAAD and TBAD, respectively. CONCLUSIONS: Hypertension, aortic aneurysms, and chronic obstructive pulmonary disease were the most prevalent comorbidities. The 30-day mortality frequencies were consistent over time with no significant differences between sexes. The 5-year mortality rate was higher for TAAD than TBAD. If the patient survived 30 days from dissection, the mortality rate for patients with TAAD was comparable with that of the general hypertensive population, but the mortality rate was significantly higher in patients with TBAD.

Intake of marine and plant-derived n-3 fatty acids and development of atherosclerotic cardiovascular disease in the Danish Diet, Cancer and Health cohort.

PURPOSE: The objective of this study was to investigate the association between intake of seafood and plant-derived n-3 polyunsaturated fatty acids (PUFA) and development of total atherosclerotic cardiovascular disease (ASCVD) and acute major ischemic events. METHODS: A total of 53,909 men and women were enrolled between 1993 and 1997 into the Danish Diet, Cancer and Health cohort and followed through nationwide Danish registries for development of total ASCVD defined as a first registration of myocardial infarction, peripheral artery disease, or ischemic stroke due to large artery atherosclerosis or small-vessel occlusion. At recruitment, the intake of the major marine n-3 PUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the plant-derived n-3 PUFA, alpha-linolenic acid (ALA), was assessed using a validated food frequency questionnaire. Statistical analyses were conducted using sex-stratified multivariable Cox proportional hazard regression models. RESULTS: During a median of 13.5 years of follow-up, 3958 participants developed ASCVD including 3270 patients with an acute major ischemic event. In multivariable analyses including adjustment for established risk factors, we found no associations for intake of ALA, but indications of inverse associations between intake of EPA, DHA and EPA + DHA and the rate of total ASCVD and acute major ischemic events. CONCLUSIONS: A high intake of marine n-3 PUFA was associated with a lower risk of total ASCVD and acute major ischemic events, whereas no association could be demonstrated for the plant-derived ALA.

Plant n-3 PUFA intake may lower the risk of atherosclerotic cardiovascular disease only among subjects with a low intake of marine n-3 PUFAs.

The role of the major plant-derived n-3 PUFA, alpha-linolenic acid (ALA), on the risk of atherosclerotic cardiovascular (ASCVD) remains unclear, but most studies have reported no association. However, the association between intake of ALA and the risk of ASCVD may depend on the intake of marine n-3 PUFAs. We investigated this hypothesis among more than 53,909 middle-aged, Danish men and women followed for a median of 13.4 years. We found a statistically significant inverse association between ALA intake modelled as a restricted cubic spline and the rate of ASCVD in subjects with a low intake of marine n-3 PUFAs, while no association was observed among subjects with a higher intake of marine n-3 PUFAs. Our findings suggest that the intake of ALA may be associated with a lower risk of total ASCVD, but only among subjects with a low intake of marine n-3 PUFAs.

Adipose tissue content of alpha-linolenic acid and development of peripheral artery disease: a Danish case-cohort study.

PURPOSE: The aim of this study was to investigate the association between adipose tissue content of the plant-derived n-3 fatty acid, alpha-linolenic acid, and the rate of incident peripheral artery disease (PAD). METHODS: We conducted a case-cohort study nested within the Danish Diet, Cancer and Health cohort (n = 57,053), which was established between 1993 and 1997. Potential PAD cases were identified using linkage with The Danish National Patient Register and all potential cases were validated. Adipose tissue samples from the buttock were collected at baseline and fatty acid composition was determined in cases and in a random sample (n = 3500) from the cohort by gas chromatography. Statistical analyses were performed using weighted Cox regression allowing for different baseline hazards among sexes. RESULTS: During a median of 13.5 years of follow-up, we identified 863 PAD cases with complete information. The median adipose tissue content of ALA in the sub-cohort (n = 3197) was 0.84% (interquartile range 0.73-0.94%) of total fatty acids. In multivariate analyses including adjustment for established risk factors, we observed a U-shaped association between ALA in adipose tissue and rate of PAD, but the association was not statistically significant (P = 0.131). Similar pattern of associations were observed between ALA content in adipose tissue and the rate of PAD among men and women. CONCLUSIONS: We found indications of a U-shaped association between adipose tissue content of ALA and the rate of PAD, but the association was not statistically significant.

Intake of α-linolenic acid is not consistently associated with a lower risk of peripheral artery disease: results from a Danish cohort study.

Intake of the plant-derived n-3 fatty acid α-linolenic acid (ALA) has been associated with anti-atherosclerotic properties. However, information on the association between ALA intake and development of peripheral artery disease (PAD) is lacking. In this follow-up study, we investigated the association between dietary intake of ALA and the rate of PAD among middle-aged Danish men and women enrolled into the Danish Diet, Cancer and Health cohort between 1993 and 1997. Incident PAD cases were identified through the Danish National Patient Register. Intake of ALA was assessed using a validated FFQ. Statistical analyses were performed using Cox proportional hazard regression allowing for separate baseline hazards among sexes and adjusted for established risk factors for PAD. During a median of 13·6 years of follow-up, we identified 950 valid cases of PAD with complete information on covariates. The median energy-adjusted ALA intake within the cohort was 1·76 g/d (95 % central range: 0·94-3·28). In multivariable analyses, we found no statistically significant association between intake of ALA and the rate of PAD (P = 0·339). Also, no statistically significant associations were observed in analyses including additional adjustment for co-morbidities and in sex-specific analyses. In supplemental analyses with additional adjustment for potential dietary risk factors, we found a weak inverse association of PAD with ALA intake above the median, but the association was not statistically significant (P = 0·314). In conclusion, dietary intake of ALA was not consistently associated with decreased risk of PAD.

Substitution of poultry and red meat with fish and the risk of peripheral arterial disease: a Danish cohort study.

PURPOSE: The aims of this study were to examine associations between substitutions of poultry and red meat intake with fish (total, lean or fatty) and the risk of peripheral arterial disease (PAD). We hypothesised that a higher intake of fish and a concomitant lower intake of poultry or red meat were associated with a lower risk of incident PAD. METHODS: We used data from a Danish cohort where middle-aged participants filled in food frequency and lifestyle questionnaires at baseline. During follow-up, we identified participants with valid diagnoses of PAD and analysed data by multivariable Cox regression analyses. Substitutions of 150 g/week of either poultry, red meat (processed or unprocessed) with 150 g/week of fish (total, lean or fatty) were explored. RESULTS: We followed the cohort (n = 54,597) for a median of 13.6 years and identified 897 cases with PAD. We found modest lower rates of PAD when intake of fish replaced a concomitant lower intake of unprocessed (HR 0.94, 95% CI 0.88-1.01) and processed red meat (HR 0.94, 95% CI 0.87-1.02). Replacing unprocessed (HR 0.89, 95% CI 0.79-1.00) or processed red meat (HR 0.88, 95% CI 0.78-1.01) with fatty fish was associated with lower rates of PAD. No associations were observed when fish intake replaced poultry or when lean fish replaced red meat. CONCLUSIONS: This study suggests that substituting red meat with fish and especially fatty fish may be associated with a lower risk of PAD, although not statistically significant. Replacing poultry with fish was not associated with the risk of PAD.

Aortic Dissections in the Population-Based Danish National Patient Registry from 1996-2016: A Validation Study.

PURPOSE: This study evaluated the validity of the ICD-10 diagnostic codes for aortic dissections (ADs) in the Danish National Patient Registry (DNPR) based upon positive predictive values (PPV). PATIENTS AND METHODS: Cases registered in the DNPR with the unspecific AD diagnostic code DI710 (unspecified AD) from 1996 to 2016, and the specific AD diagnostic codes DI710A (AD Type A) and DI710B (AD Type B) from 2006 to 2016, were included. Available medical records from all registered cases underwent review. Confirmed cases of AD served as "gold standard" when reporting PPV. PPV estimates were stratified by regional differences, date, age at time of diagnosis, and sex. RESULTS: A total of 5018 cases were identified in the DNPR. After merging of data and retrieval of medical records, 3767 cases were eligible for validation. Of these, 2677 cases were verified as AD type A (59.7%), AD type B (38.8%), and unspecified type of AD (1.5%). The average age at diagnosis was 65.1 ±13.0 years (67.3% males). The overall PPV for having an AD when one of the three diagnostic codes were registered from 1996 to 2016 was 71.1% (95% confidence interval (CI): 69.6-72.5) and increased significantly over time. From 2006 to 2016, the PPV for the specific AD diagnostic codes was 89.5% (95% CI: 87.4-91.3), whilst the PPV for the unspecific diagnostic code was 63.5% (95% CI: 61.1-65.9). CONCLUSION: We found the overall PPV for the pooled AD diagnostic codes in the DNPR acceptable. However, the two specific AD diagnostic codes presented remarkably higher PPV compared to the unspecific diagnostic code.

Intake of marine n-3 polyunsaturated fatty acids and the risk of incident peripheral artery disease.

BACKGROUND: A high intake of marine n-3 polyunsaturated fatty acids (PUFAs) may lower the risk of coronary heart disease and ischemic stroke. The association between intake of marine n-3 PUFAs and development of peripheral artery disease (PAD), however, remains unexplored. We hypothesised that intake of marine n-3 PUFAs, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and the sum of EPA + DHA was associated with a lower risk of incident PAD. METHODS: We used data from the Danish Diet, Cancer and Health cohort and investigated the associations between intake of EPA, DHA and EPA + DHA and development of PAD. Information on intake of n-3 PUFAs was obtained through a validated food frequency questionnaire. Potential PAD cases were identified through linkage to the Danish National Patient Register and subsequently, all cases were validated. RESULTS: Data were available from 55,248 participants and during a median of 13.6 years of follow-up, 950 cases of PAD were identified. Multivariate Cox regression analyses with adjustments for established risk factors showed no statistically significant associations between intake of EPA (p = 0.255), DHA (p = 0.071) or EPA + DHA (p = 0.168) and the rate of incident PAD. CONCLUSIONS: We did not confirm our hypothesis that intake of EPA, DHA or EPA + DHA was associated with a lower risk of incident PAD.

Marine and plant-based n-3 PUFA and atherosclerotic cardiovascular disease.

n-3 PUFA may exert favourable effects on several processes that may inhibit the atherosclerotic process. However, the role of n-3 PUFA in lowering the risk of atherosclerotic CVD (ASCVD) has been fiercely debated. In the present paper, we summarise the main findings from previous follow-up studies of intake and studies using adipose tissue as an objective biomarker to investigate exposure to n-3 PUFA in relation to ASCVD risk and discuss some perspectives for further research. The majority of previous studies investigating intake of marine- and plant-based n-3 PUFA have focused on CHD while other ASCVD such as ischaemic stroke and peripheral artery disease have been less studied. However, recent data from Danish Diet, Cancer and Health cohort suggest that marine n-3 PUFA may be inversely associated with risk of myocardial infarction, ischaemic stroke and peripheral arterial disease caused by atherosclerosis. The effect of the plant-derived n-3 PUFA α-linolenic acid on ASCVD is less clear and several gaps in the literature remain to be explored.

Marine n-3 Fatty Acids and the Risk of Peripheral Arterial Disease.

BACKGROUND: The content of marine n-3 polyunsaturated fatty acids (PUFAs) in adipose tissue is considered a long-term biomarker for the body's endogenous exposure to seafood. OBJECTIVES: This study sought to examine associations between the content of marine n-3 PUFAs in adipose tissue and the risk of incident peripheral arterial disease (PAD). METHODS: In this case-cohort study based on data from the Danish Diet, Cancer and Health cohort, adipose tissue biopsies were taken from the buttocks of all participants at baseline. After a median follow-up of 13.5 years, 870 validated cases of PAD were identified and included together with a randomly drawn subcohort of 3,204 participants using weighted Cox regression. Adipose tissue samples were analyzed by gas chromatography. RESULTS: In multivariable analyses using the lowest quintile as the reference and adjusting for established risk factors for PAD, we found a statistically significant lower rate of PAD in the highest quintile of eicosapentaenoic acid (EPA) (hazard ratio [HR]: 0.55; 95% confidence interval [CI]: 0.41 to 0.74) and a nonsignificant lower rate for docosahexaenoic acid (HR: 0.79; 95% CI: 0.59 to 1.06). We observed a lower rate of PAD, when comparing the highest quintile of the combined EPA and docosahexaenoic acid with the reference (HR: 0.71; 95% CI: 0.53 to 0.96). In contrast, docosapentaenoic acid had an HR of 1.31 (95% CI: 0.97 to 1.77) in the highest quintile. CONCLUSIONS: A high content of marine n-3 PUFAs in adipose tissue, in particular EPA, was associated with a lower risk of incident PAD.