Randomised comparison of the effects of nicardipine and esmolol on coronary artery wall stress: implications for the risk of plaque rupture

Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy

PURPOSE

Blunt aortic injuries (BAI) have historically been considered an indication for emergent surgical intervention. Nevertheless, the observation that the outcome of the concomitant traumatic injuries has a major impact on prognosis and the rise of thoracic endovascular aortic repair (TEVAR) as an effective therapy for BAI have significantly changed in recent years the treatment algorithm of this condition. Our objective was to identify findings associated with the aortic injury which would be the best predictor of prognosis, with the objective of guiding the decision-making process for selecting the optimal timing of aortic repair.

METHODS

We reviewed blunt aortic injuries from 3 Level I Trauma Centers from July 2008 to December 2016. We analyzed overall and BAI-related 30-day mortality in relation to: hemodynamics, timing of treatment, TEVAR vs open repair, and aortic injury grade as defined by the Society for Vascular Surgery. Based on computed tomographic angiography (CT scan) imaging, we selected the radiologic aortic findings most indicative of high mortality risk, which we defined as "Radiographic Severe Injury" (RSI): (1) total/partial aortic transection, (2) active contrast extravasation, or (3) the association of 2 of more of the following: contained contrast extravasation > 10 mm, periaortic hematoma, and/or mediastinal hematoma with thickness > 10 mm, or significant left pleural effusion.

RESULTS

Of a total of 76 consecutive patients, 50 (66%) underwent immediate repair, 24 (31%) delayed aortic repair, and 2 (3%) died prior to repair. 58 patients (76%) had TEVAR, while 16 (24%) had open repair. Overall mortality was 18% and BAI-related mortality was 13%. In BAI-related mortalities, 70% of patients had RSI. Patients with high risk of overall mortality had hypotension and tachycardia (SBP < 100, HR ≥ 100), high ISS, and required vasopressors. Factors only associated with BAI-related mortality included RSI.

CONCLUSION

CT scan findings suggestive of RSI are predictive of mortality associated with BAI. Radiologic assessment of the severity of the aortic injury with characterization for the presence of RSI may represent the key factors to determine the optimal timing of treatment of the aortic injury and guide the overall treatment strategy.

LEVEL OF EVIDENCE

IV.

Combination therapy as first-line treatment for hypertension

Systemic hypertension is a long-term risk factor for the development of atherosclerotic vascular disease and when uncontrolled is a short-term trigger of acute vascular events such as acute coronary syndromes and stroke. Thus, rapid reduction in BP is desirable. Patients at high risk for vascular disease, such as those with diabetes mellitus, have aggressive goal BP targets because studies have shown that achieving these targets reduces events. Given the dual goals in high-risk patients of reducing BP quickly and to aggressively low targets, the classic 'step therapy' of one drug titrated at a time to reduce BP is inadequate. Combination therapy with at least two potent medications makes more sense, and manufacturers are now increasing their offerings of single-pill combinations for hypertension. Combination pills are popular with patients and increase compliance with therapy. Many believe that renin-angiotensin aldosterone system (RAAS) blockers are the cornerstone of hypertension treatment in patients at high risk for vascular disease. The newer combination pills include a RAAS blocker and diuretics or a long-acting calcium channel antagonist (CCA). Recent studies have shown that a RAAS blocker plus a dihydropyridine CCA is superior to older diuretic-based combinations for preventing cardiovascular events. These considerations support a new approach to the higher risk hypertensive patient: effective doses of RAAS blocker/CCA combination pills to rapidly lower BP to <130/80 mmHg.

Are we misunderstanding beta-blockers

In myocardial ischaemia and heart failure, beta-blockers with intrinsic sympathomimetic activity (ISA) e.g. pindolol, xamoterol, bucindolol, nebivolol, have performed poorly in reducing morbidity and mortality. In both indications beta-1 blockade is the vital active ingredient. Beta-1 blockade (bisoprolol) is now an alternative first-line choice to Ace-inhibition in the treatment of heart failure. The therapeutic role of beta-blockers in hypertension is less well understood, particularly since the new recommendations in the UK from the NICE committee stating that: 1. beta-blockers are no longer preferred as a routine initial therapy, 2. the combination with diuretics is discouraged due to the risk of induced diabetes, and 3. in younger patients first-choice initial therapy should be an ACE-inhibitor. Recent data from the Framingham Heart Study and other epidemiological studies have indicated that the development of diastolic hypertension in younger subjects is closely linked to weight-increase and an increase in peripheral resistance; such subjects have a high adrenergic drive and cardiac output. In contrast, elderly systolic hypertension mostly arises de novo via poor vascular compliance. Thus in younger, probably overweight, hypertensives (including diabetics) first-line beta-blockade has performed well in preventing myocardial infarction (a fact hidden by meta-analyses that do not take age into account). Conversely, in elderly hypertensives first-line beta-blockade (atenolol) has performed poorly in reducing cardiovascular risk (due to partial beta-2 blockade atenolol evokes metabolic disturbance and does not improve vascular compliance, or effectively lower central aortic pressure or reverse left ventricular hypertrophy). Thus beta-blockers like atenolol are ill-equipped for first-line therapy in elderly hypertension. Some beta-blockers, e.g. bisoprolol (up to 10 mg/day is highly beta-1 selective) and nebivolol (beta-2/3 intrinsic sympathomimetic activity), do improve vascular compliance and cause no metabolic disturbance. Beta-blockers as second-line to low-dose diuretics (which, by improving vascular compliance and increasing sympathetic nerve activity, create an optimal environment for beta-blockade) in elderly hypertension (including diabetics) have performed well in reducing cardiovascular events (this combination has the added bonus of reducing the risk of bone fracture by about 30%). Meta-analyses which include studies where it is unclear whether a diuretic or beta-blocker was a first-line therapy will dilute the benefit stemming from first-line diuretic/second-line beta-blockade. Hypertensives (of all ages) with ischaemia are well suited to beta-blockade.

Significance of beta-blockers in the perioperative period

Beta-blockers have emerged as one of the key therapeutic agents that can decrease cardiac morbidity and mortality. Advances in cardiac beta-adrenergic receptor physiology and pharmacology have provided new insights into the beneficial effects of beta-blockers in cardiovascular medicine. Although significant advances have been made, many specific questions still remain to be answered. We will review some of these developments and the current role of beta-blockers in peri-operative medicine.