Vascular Dysfunction: Sequelae of AcuteHypertension

Overview

• Introduction: Scope of the problem

• Effects of acute BP elevation on the vessel wall

• Traditional parenteral antihypertensive treatment– Pharmacokinetic profiles and key clinical studies– Guidelines for use

• Clinical trial update: New paradigm in management of acute hypertension

Chronic hypertension

Hypertensiveemergencies

Acute vascular reactivity

Courtesy of S Aronson, MD.

Acute and chronic hypertension: Clinical context

Sympathetic overactivation drives acute hypertension

Calhoun DA, Oparil S. N Engl J Med. 1990;323:1177-83.Cheung AT. J Card Surg. 2006;21(suppl):S8-14.Weitz HH. Med Clin North Am. 2001;85:1151-69.

Sympathetic overactivation

Acute hypertension

ArteriosclerosisChronic hypertension

Important triggers include clonidine withdrawal, cocaine abuse, certain surgical settings

FLOWFLOW

PRESSUREPRESSURE

HR x SV = COBP*/ CO = SVR

CO x MAP = work MAP = 1/3 PP + DBP

All in the absence of pulsations

Components of blood pressure: New focus on pulse pressure

Courtesy of S Aronson, MD.

Perioperative ISH associated with postoperative adverse events

Event rate (%) Odds ratio

No ISH (n = 1457)

ISH (n = 612)

Renal failure/insufficiency 6.7 8.8 1.3 (0.9-1.9)

Stroke 6.3 10.1 1.7 (1.2-2.3)

LV dysfunction 29.1 34.3 1.3 (1.0-1.6)

Renal failure/insufficiency, stroke, LV dysfunction, death

33.2 40.9 1.4 (1.1-1.7)

Aronson S et al. Anesth Analg. 2002;94:1079-84.

N = 2069 scheduled for CABG

ISH = isolated systolic hypertension

Proposed risk index for renal dysfunction/failure post-CABG: Importance of pulse pressure

Preoperative risk factors Score Intraoperative risk factors Score

Age >75 years 7 >2 Inotropes 10

Pulse pressure (mm Hg) 40 41-60 61-80 81-100 >100

0481216

Intra-aortic balloon pump

Cardiopulmonary bypass ≥122 min

15

6

History CHF MI Renal disease

9613

Aronson S et al. Circulation. 2007;115:733-42.

N = 4801 scheduled for bypass

Multicenter Study of Perioperative Ischemia (McSPI)

Acute hypertension: Subgroups and settings

Acute hypertension

Hypertensive urgency

Hypertensive emergency

Perioperative hypertension

Operating roomPostanesthesia care

Emergencydepartment

Intensive care unit

JNC 7 definitions

Hypertensive emergency BP >180/120 mm Hg complicated by evidence of impending or progressive end-organ damage

Hypertensive urgency Severe elevation in BP without progressive end-organ damage

Chobanian AV et al. Hypertension. 2003;42:1206-52.

Hypertensive urgencies/emergencies: Patients and organ systems at risk

Cardiopulmonary• ADHF• ACS• Acute pulmonary edema• Acute aortic syndromes

Neurovascular• Hypertensive encephalopathy• Stroke

Ocular• Papilloedema

Renal• Acute renal dysfunction

Calhoun DA, Oparil S. N Engl J Med. 1990;323:1177-83.Marik PE, Varon J. Chest. 2007;131:1949-62.

ACS = acute coronary syndromeADHF = acute decompensated heart failure

1% of hypertensives (1990 data). Contemporary prevalence may be lower

Hypertensive urgencies/emergencies: Prevalence of organ system complications

Incidence (%)

CNS

Cerebral infarction 24.5

Hypertensive encephalopathy 16.3

Intracerebral/subarachnoid hemorrhage 4.5

CV

Pulmonary edema 22.5

Acute congestive heart failure 14.3

ACS 12.0

Eclampsia 4.5

Aortic dissection 2.0

N = 449 presenting to Emergency Department with hypertensive urgency/emergency

Zampaglione B et al. Hypertension. 1996;27:144-7.

Hypertensive urgencies/emergencies: Most common presenting symptoms

Urgencies

• Headache (22%)

• Epistaxis (17%)

• Faintness and psychomotor agitation (10%)

Emergencies

• Chest pain (27%)

• Dyspnea (22%)

• Neurological deficit (21%)

Zampaglione B et al. Hypertension. 1996;27:144-7.

Perioperative hypertension: Scope of the problem

• Generally acknowledged to be common but little data available on exact prevalence in contemporary surgical practice

• Markers of increased risk for perioperative ↑BP include:– History of hypertension– Type of surgery

• Cardiac• Carotid• Peripheral vascular• Abdominal aortic• Intraperitoneal/intrathoracic• Pheochromocytoma tumor

Skarvan K. Curr Opin Anaesthesiol. 1998;11:29-35.Weitz HH. Med Clin North Am. 2001;85:1151-69.

Erstad BL, Barletta JF. Ann Pharmacother. 2000;34:66-79.

Perioperative antihypertensive therapy is common in cardiac surgery

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Preoperative Intraoperative Postoperative ICU

Patients (%)

Prior hypertension (n = 845)

No prior hypertension (n = 815)

Vuylsteke A et al. J Cardiothorac Vasc Anesth. 2000;14:269-73.

N = 1660 patients, (N = 191 anesthesiologists)

Mean MAP threshold for treatment (mm Hg)

106.0 86.3 97.1 109.0