vascular dysfunction: sequelae of acute hypertension
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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