Incidence of acute aortic dissections in patients with out of hospital cardiac arrest: A systematic review and meta-analysis of observational studies

Long-Term Impact of the Kumamoto Earthquake on Out-of-Hospital Cardiac Arrest With Cardiac and Non-Cardiac Origins - An Interrupted Time Series Analysis

BACKGROUND

Possible etiologies of out-of-hospital cardiac arrest (OHCA), including aortic dissection, ruptured aortic aneurysms, and pulmonary embolism, may be classified as non-cardiac causes. We investigated whether cardiac and non-cardiac OHCAs increased following the Kumamoto earthquake and whether the impact on OHCAs extended to regions far from the epicenter.

METHODS AND RESULTS

We prospectively analyzed a nationwide registry of patients who experienced OHCAs between January 2013 and December 2019. Data from cases registered in 7 prefectures, including Kumamoto (Kyushu region; n=82,060), in the All-Japan Utstein Registry were analyzed for OHCAs of cardiac and non-cardiac origin. The numbers of OHCAs before and after the Kumamoto earthquake were compared using an interrupted time series analysis. The incidence of both cardiac (rate ratio [RR] 1.22) and non-cardiac (RR 1.27) OHCAs in Kumamoto Prefecture increased after the earthquake. The difference disappeared when the analysis was limited to patients with non-cardiac OHCAs with a clear cause of cardiac arrest. The number of cardiac and non-cardiac OHCAs did not increase in other prefectures within the Kyushu region.

CONCLUSIONS

The Kumamoto earthquake led to an increase in the incidence of cardiac and non-cardiac OHCAs. However, this was attenuated by increasing distance from the epicenter. Except for cardiac causes, cases complicated by earthquake-related events may include non-cardiac OHCAs due to vascular diseases that might be overlooked.

Pre-hospital heparin is not associated with infarct vessel patency and mortality in ST-segment elevation myocardial infarction patients with out-of-hospital cardiac arrest

BACKGROUND

Pre-hospital heparin administration has been reported to improve prognosis in patients with out-of-hospital cardiac arrest (OHCA). This beneficial effect may be limited to the subgroup of ST-segment elevation myocardial infarction (STEMI) patients.

METHODS

To assess the impact of pre-hospital heparin loading on TIMI (Thrombolysis in Myocardial Infarction) flow grade and mortality in STEMI patients with OHCA, we analyzed data from 2,566 consecutive patients from two hospitals participating in the prospective Feedback Intervention and Treatment Times in ST-segment Elevation Myocardial Infarction (FITT-STEMI) trial.

RESULTS

In 394 participants with OHCA, 272 (69%) received heparin from the emergency medical service (EMS). Collapse witnessed by EMS (odds ratio (OR) = 3.53, 95%-confidence interval (CI) = 1.54-8.09; p = 0.003) and pre-hospital ECG recording (OR = 3.32, 95% CI = 1.06-10.35; p = 0.039) were identified as parameters significantly associated with pre-hospital heparin use. In univariate analysis, in-hospital mortality was lower in the group receiving heparin in the pre-hospital setting (26.8% vs. 42.6%, p = 0.002). However, in a regression model, pre-hospital heparin use was no longer a significant predictor of mortality (OR = 0.992; p = 0.981). Patency of the infarct artery prior to coronary revascularization, as measured by TIMI flow grade, was not associated with pre-hospital administration of heparin in OHCA patients (OR = 0.840; p = 0.724).

CONCLUSIONS

In STEMI patients with OHCA, pre-hospital use of heparin is neither associated with improved early patency of the infarct artery nor with a better prognosis. Our results do not support the assumption of a positive effect of heparin administration in the pre-hospital treatment phase in STEMI patients with OHCA.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00794001.

Diagnosis and management of acute aortic dissection in the emergency department

Acute aortic dissection is often misdiagnosed as a result of its atypical presentations. It affects 4000 patients a year in the UK of all ages, not just older patients, with increasing numbers of cases expected in the future because of the ageing population. Dissection of the aortic wall leads to sudden, severe pain, and commonly end-organ symptoms which must be recognised. Acute aortic dissection can be challenging to diagnose in the emergency department because of the multitude of possible presentations and the need for selective testing with Computed Tomography Angiography (CTA). Clinicians often miss acute aortic dissection because it is not considered in the differential diagnosis, and the challenge lies in identifying acute aortic dissection in a sea of complaints of chest, back and abdominal pain. There are several ways to improve diagnosis, including awareness campaigns, better education about patients in which to consider acute aortic dissection, and improved detection strategies including which patients should receive CTA. Clinical decision tools and biomarkers could help, but further research is required and is a research focus in emergency medicine. Once diagnosed, blood pressure control, analgesia and urgent surgery or transfer to enable this to occur with minimal delay is required.

Height and body surface area versus wall stress for stratification of mid-term outcomes in ascending aortic aneurysm

Objectives

Current diameter-based guidelines for ascending thoracic aortic aneurysms (aTAA) do not consistently predict risk of dissection/rupture. ATAA wall stresses may enhance risk stratification independent of diameter. The relation of wall stresses and diameter indexed to height and body surface area (BSA) is unknown. Our objective was to compare aTAA wall stresses with indexed diameters in relation to all-cause mortality at 3.75 years follow-up.

Methods

Finite element analyses were performed in a veteran population with aortas ≥ 4.0 cm. Three-dimensional geometries were reconstructed from computed tomography with models accounting for pre-stress geometries. A fiber-embedded hyperelastic material model was applied to obtain wall stress distributions under systolic pressure. Peak wall stresses were compared across guideline thresholds for diameter/BSA and diameter/height. Hazard ratios for all-cause mortality and surgical aneurysm repair were estimated using cause-specific Cox proportional hazards models.

Results

Of 253 veterans, 54 (21 %) had aneurysm repair at 3.75 years. Indexed diameter alone would have prompted repair at baseline in 17/253 (6.7 %) patients, including only 4/230 (1.7 %) with diameter < 5.5 cm. Peak wall stresses did not significantly differ across guideline thresholds for diameter/BSA (circumferential: p = 0.15; longitudinal: p = 0.18), but did differ for diameter/height (circumferential: p = 0.003; longitudinal: p = 0.048). All-cause mortality was independently associated with peak longitudinal stresses (p = 0.04). Peak longitudinal stresses were best predicted by diameter (c-statistic = 0.66), followed by diameter/height (c-statistic = 0.59), and diameter/BSA (c-statistic = 0.55).

Conclusions

Diameter/height improved stratification of peak wall stresses compared to diameter/BSA. Peak longitudinal stresses predicted all-cause mortality independent of age and indexed diameter and may aid risk stratification for aTAA adverse events.