Optimal Medical Management of Type B Dissections: What is it and

have there been any advances in this modality?

David Rigberg, MD

Professor of Surgery

UCLA/DGSOM

May 23, 2019

No disclosures

Medial Tx Type B Dissection

• Not rigorously studied

• Expert opinion

• Anecdotal experience

• Observational studies

. Circ Res. 1970 Jul;27(1):121-7.

Historical Support

• Postulated that shape of waveform is key-impact of contractility-reserpine (indole alkaloid – depleted catechol)-trimethaphan (blocks cholinergic reception)

• Created a system with Tygon tubing and dog aortas

• Little dissection progression with non-pulsatile flow

• Progression/rate related to dp/dtmax (rate of pressure change)

Medical Treatment

• Rapid recognition and diagnosis

• Goal is reduction of bp to 100-120 mmHg

• HR < 60 bpm

• Maintain CO for adequate perfusion

• Pain control

• Careful monitoring for complications

• Planning for conversion to oral meds

Pain

• Morphine typically used

• Pain/stress control needed for BP control

• Role of catecholamines

• Persistent pain requires continued reassessment!

Beta-blockade

• Propranolol, metoprolol, labetolol, esmolol

• All can be given iv

• All decrease contractility and reduce HR

• Used in both acute and chronic treatment

• Can be contraindicated-2nd or 3rd degree heart block-bronchospasm

Agents

• Esmololultra short-actingt1/2 is 9 minutesuseful for testing tolerancecan be stopped abruptly

• Labetololmore generalized impactalpha, beta 1 and beta 2

• Metoprololselective beta 1

Calcium Channel Blockade

• Non-hydropyridine agents

• Relatively selective for myocardiumverapamil – more selectivediltiazem – between verapamil and hydropyr.

• Negative inotrope and chronotrope

• Use carefully with B-blockade

Sodium nitroprusside

• Works by releasing nitric oxide

• Vasodilator

• Decreases preload and afterload

• Need to consider reflex tachy and contractility-Can increase dp/dt-Need to block before administration

• Side effects potentiated if renal failure…

Other Agents

• Nitroglycerinalso works by NO (mitochondrial aldehyde dehydrogenase)low dose – preloadhigh dose – afterload

• Fenoldopamvasodilator via peripheral D1 receptorsrapid onset (4 minutes)short duration (10 minutes)

European Society of Cardiology

European Guidelines

• Originally published 2010

• MSO4 for pain

• Beta-blocker with goal 100-120mm Hg-propranolol 0.05-0.15 mg/kg Q4-6 h-esmolol 0.5 mg/kg LD and 0.1-0.2 mg/kg/min-need to watch volume! (max 10 mg/ml)

• Nitroprusside as additional agent -0.25 mics/kg/min

• Calcium Channel blocker if bronchospasm

Japanese Circulation Society

Guidelines

• MSO4 or buprenorphine for pain

• Beta-blockers titrated to HR < 50

• Questioned role of tight BP control for preventing aneurysm formation (s/p d/c)

• TEVAR recognized as useful for complicated cases

American (AHA/ACC) Guidelines

American Guidelines

• IV beta-blockade to HR < 60 bpm

• Non-dihydro CCB’s alternate for rate control

• For BP >120 mm Hg despite above, ACEi or other vasodilator to reduce BP that maintains adequate end-organ perfusion…

• Beta-blockers with caution with AR

• Vasodilators after rate control (III C)

Level of Evidence for Recommendations…

Outcomes

• Most (70%) Type B patients hypertensive at admit, but most normotensive (89.8%) at d/c

• 96% d/c’d with BP meds-89% Beta-blockers-50.3% Ca channel blockers-46.7% 46.7% ACEi’s-28.9% diuretics-22% vasodilators

Outcomes

• Beta-blockers and Calcium channel blockers are both associated with improved long term survival in acute Type B patients

• Calcium channel blockers associated with reduced aortic expansion

• Weaker evidence for ARB’s (particularly in Marfans’), statins

IRA

D D

ATA

BA

SE

• Most required at least two IV meds (80%)

• Median time to control pain → 48h

• Mean hospital stay 15 days

• Mean ICU stay 8 days

Estrera et al. Circulation 2006; 114: I-384-389

• Jan 2001-March 2005

• 129 consecutive Type B dissections with initial medical management

• In-hospital mortality 10.1%– 19% when intervention was required

– 8.3% when able to treat medically

Estrera et al. Circulation 2006; 114: I-384-389

Follow-up of medically treated pts

• Median follow-up 18.5 months

• One year survival 81.6% (Four year 72.3%)

• Intermediate surgical procedures in 6/116 – 4 due to expansion

• Independent risk factor for hospital mortality was rupture

• Independent risk factors for midterm death were history of COPD and low GFR (<57 mL/min)

Estrera et al. Circulation 2006; 114: I-384-389

Initial Medical Treatment

Cardiovascular Fellows’ Bootcamp 2010: Get The Basics

✓Maintain systolic BP 100-120mmHg

✓Maintain HR < 60 bpm (reduces secondary adverse events)

IRAD Data:•73% of patients managed conservatively

•10% in-hospital mortality

•60-80% survival rate at 4-5 years

•40-45% survival rate at 10 years

Have there been any advances in this modality?

No