Vascular Dysfunction: Sequelae of Acute Hypertension

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 Hypertensive emergencies 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: Cheung AT. J Card Surg. 2006;21(suppl):S8-14. Weitz HH. Med Clin North Am. 2001;85: Sympathetic overactivation Acute hypertension Arteriosclerosis Chronic hypertension Important triggers include clonidine withdrawal, cocaine abuse, certain surgical settings

FLOW PRESSURE HR x SV = CO BP*/ 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 ( ) Stroke ( ) LV dysfunction ( ) Renal failure/insufficiency, stroke, LV dysfunction, death ( ) Aronson S et al. Anesth Analg. 2002;94: N = 2069 scheduled for CABG ISH = isolated systolic hypertension

Proposed risk index for renal dysfunction/failure post-CABG: Importance of pulse pressure Preoperative risk factorsScoreIntraoperative risk factorsScore Age >75 years7>2 Inotropes10 Pulse pressure (mm Hg) > Intra-aortic balloon pump Cardiopulmonary bypass ≥122 min 15 6 History CHF MI Renal disease Aronson S et al. Circulation. 2007;115: 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 room Postanesthesia care Emergency department Intensive care unit

JNC 7 definitions Hypertensive emergencyBP >180/120 mm Hg complicated by evidence of impending or progressive end-organ damage Hypertensive urgencySevere elevation in BP without progressive end-organ damage Chobanian AV et al. Hypertension. 2003;42:

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: Marik PE, Varon J. Chest. 2007;131: ACS = acute coronary syndrome ADHF = 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 infarction24.5 Hypertensive encephalopathy16.3 Intracerebral/subarachnoid hemorrhage4.5 CV Pulmonary edema22.5 Acute congestive heart failure14.3 ACS12.0 Eclampsia4.5 Aortic dissection2.0 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: Weitz HH. Med Clin North Am. 2001;85: Erstad BL, Barletta JF. Ann Pharmacother. 2000;34:66-79.

Perioperative antihypertensive therapy is common in cardiac surgery Vuylsteke A et al. J Cardiothorac Vasc Anesth. 2000;14: N = 1660 patients, (N = 191 anesthesiologists) Mean MAP threshold for treatment (mm Hg)