In a patient with severe vertebral artery stenosis whose chronic antihypertensive regimen was held during an acute gallbladder infection and was treated only with PRN antihypertensives for systolic blood pressure >180 mm Hg, did the subsequent stroke result from uncontrolled hypertension rather than malpractice?

Stroke Causation in Vertebral Stenosis with Held Antihypertensives

The stroke was most likely caused by hypoperfusion from uncontrolled hypertension in the setting of severe vertebral artery stenosis, representing a complex clinical scenario where standard blood pressure management guidelines may not apply—this is not straightforward malpractice but rather highlights the challenging balance between treating acute infection and maintaining cerebral perfusion in patients with critical stenosis. 1, 2

Understanding the Mechanism

Hemodynamic Stroke Risk in Vertebral Stenosis

• Patients with severe vertebral artery stenosis are uniquely vulnerable to hypoperfusion strokes when blood pressure drops, as they rely on elevated systemic pressure to maintain adequate cerebral blood flow through critically narrowed vessels 1, 2
• The VERiTAS study specifically demonstrated that patients with vertebrobasilar disease and low flow who had BP controlled to <140/90 mmHg had a 4.5-fold increased risk of subsequent stroke (HR 4.5,95% CI 1.3-16.0, P=0.02) compared to those with higher blood pressures 2
• In vertebrobasilar territory ischemia with bilateral vertebral stenosis, induced hypertension has been shown to produce rapid clinical improvement, demonstrating the hemodynamic dependence of these patients 3

The Acute Stroke Guidelines Context

• AHA/ASA guidelines explicitly warn that aggressive blood pressure lowering in acute stroke is associated with neurological worsening 1, 4, 5
• Each 10% decline in blood pressure during acute stroke is associated with an odds ratio of 1.89 for unfavorable outcomes 1
• Drops in systolic or diastolic BP >20 mmHg are associated with early neurological worsening, higher rates of poor outcomes or death, and larger infarction volumes 1
• Early administration of antihypertensives to patients with SBP >180 mmHg was associated with marked increases in early deterioration, poor neurological outcome, or death 1

The Clinical Decision-Making Dilemma

Standard Acute Stroke BP Management

• For patients NOT receiving thrombolytics, antihypertensive agents should generally be withheld unless SBP >220 mmHg or DBP >120 mmHg 1, 4, 5
• The threshold of SBP >180 mmHg used for PRN treatment in this case falls below the recommended treatment threshold and may have been inappropriate 1, 4
• When treatment is indicated, BP should be lowered cautiously by only 15-25% within the first 24 hours to avoid compromising cerebral perfusion 1, 4, 5

Special Considerations for Vertebral Stenosis

• In symptomatic patients with severe vertebral artery stenosis, it is not known whether antihypertensive therapy is beneficial or harmful by reducing cerebral perfusion 1
• Guidelines acknowledge that impaired cerebrovascular reactivity in severe stenosis may be associated with increased risk of ipsilateral ischemic events 1
• For patients with severe large vessel stenosis, initial BP targets should be <140/90 mmHg (not <180 mmHg) with monitoring for hypoperfusion symptoms 6

Analyzing the Malpractice Question

Factors Supporting Clinical Complexity (Not Malpractice)

• The decision to hold chronic antihypertensives during acute gallbladder infection has physiologic rationale, as acute illness can cause hemodynamic instability 4
• Using PRN antihypertensives for SBP >180 mmHg actually represents more aggressive treatment than guidelines recommend (which suggest withholding treatment until >220 mmHg) 1, 4, 5
• The eventual restart of antihypertensives may have precipitated hypoperfusion in a patient dependent on elevated BP for cerebral perfusion through stenotic vessels 3, 2

Factors Suggesting Suboptimal Management

• Failure to recognize that severe vertebral stenosis creates a hemodynamically vulnerable state where standard BP management may not apply 1, 2
• Not obtaining urgent vascular imaging (CTA or MRA) to identify the severe stenosis before making BP management decisions 4, 7
• Uncontrolled hypertension among treated hypertensive patients accounts for 27% of ischemic strokes in the general population, but this patient's situation is reversed—the stenosis made them dependent on hypertension 8

Critical Clinical Pitfalls

What Went Wrong

• Treating BP to <180 mmHg in a patient with severe vertebral stenosis likely reduced perfusion pressure below the critical threshold needed to maintain flow through stenotic vessels 3, 2
• The PRN threshold of 180 mmHg was too aggressive for someone with critical stenosis who may have required permissive hypertension 1, 2
• Failure to perform urgent neurovascular imaging meant the team was unaware of the severe stenosis that fundamentally changed the risk-benefit calculus of BP management 4, 7

How to Avoid This Scenario

• In any patient with posterior circulation symptoms, obtain urgent vascular imaging (CTA/MRA) before making aggressive BP management decisions 4, 7
• For patients with known or suspected severe vertebrobasilar stenosis, consider permissive hypertension with BP targets of 140-160 mmHg or higher rather than aggressive control 3, 2
• Recognize that standard acute stroke BP guidelines may not apply to patients with hemodynamically significant stenosis 1, 2
• When holding chronic antihypertensives during acute illness, maintain closer BP monitoring and have a lower threshold for neuroimaging if any neurological symptoms develop 4

The Verdict on Causation

The stroke was likely multifactorial: the combination of severe vertebral stenosis creating hemodynamic vulnerability, holding of chronic antihypertensives during acute illness, and then either uncontrolled hypertension causing plaque rupture/embolism OR overly aggressive BP control causing hypoperfusion 7, 9, 2. The most probable mechanism is hypoperfusion given the severe stenosis and the evidence that lower BP in this population increases stroke risk 3, 2.

This represents a deviation from optimal care rather than clear-cut malpractice: the failure was not recognizing that severe vertebral stenosis fundamentally changes BP management, and not obtaining urgent vascular imaging to guide decisions 1, 4, 2. However, the complexity of balancing acute infection management with stroke prevention in critical stenosis makes this a challenging clinical scenario where reasonable physicians might disagree on the optimal approach 1.