Augmented Pressor Responses to Mental Stress in Females with Spontaneous Coronary Artery Dissection

Background: Spontaneous coronary artery dissection (SCAD) causes acute coronary syndrome or sudden cardiac death due to a separation of arterial wall layers. The majority of patients with SCAD are females (>80%) with few to no traditional cardiovascular risk factors. Though the physiological mechanisms that predispose to SCAD are unknown, common triggers for SCAD events include sympathoexcitatory stimuli, such as mental and emotional stress. Additionally, studies report high prevalence of depression and anxiety among patients with SCAD. Our study aimed to investigate cardiovascular responses to mental stress in patients with SCAD. We hypothesized that patients with SCAD would have exaggerated cardiovascular responses to mental stress compared to healthy controls. Methods: Four female patients with SCAD were age-, and BMI-matched with 4 healthy females. Participants underwent 2 minutes of baseline quiet rest, a 5-minute Stroop Color Word Test to induce mental stress, followed by 2 minutes of recovery. Continuous beat-to-beat blood pressure (BP, finger photoplethysmography) and heart rate (HR, 3-lead ECG) were recorded. Venous occlusion plethysmography was used to measure forearm blood flow (FBF). Forearm vascular conductance (FVC) was calculated as FBF/mean BP×100. Data are presented as change from baseline (Δmean±SD). Group data were compared using independent samples t-tests. Results: Resting hemodynamic parameters (Systolic [SBP], Diastolic [DBP], and Mean BP [MBP], Pulse pressure [PP], and HR) and FVC were similar between groups. Patients with SCAD had greater increases in DBP (Δ12±5 vs. Δ1±5 mmHg, p=0.02) and PP (Δ5±3 vs. Δ-7±8 mmHg, p=0.04) during the last minute of mental stress test compared to controls. Although, there were no differences in the changes of SBP (Δ17±7 vs. Δ-1±13 mmHg, p=0.05), MBP (Δ13±6 vs. Δ3±8 mmHg, p=0.08), HR (Δ8±0 vs. Δ10±2 bpm, p=0.12), or FVC (Δ1.5±1.2 vs. Δ1.8±1.3 ml/min/100 mmHg, p=0.80) between groups. During the last minute of recovery, there were no differences in hemodynamic parameters (SBP: Δ6±9 vs. Δ-4±10 mmHg, p=0.23; DBP: Δ2±7 vs. Δ-3±2 mmHg, p=0.22; MBP: Δ3±7 vs. Δ-3±5 mmHg, p=0.22; PP: Δ4±5 vs. Δ-1±8 mmHg, p= 0.35; HR: Δ-1±3 vs. Δ0±3 bpm, p=0.64), or FVC (Δ1.3±1.7 vs. Δ0.5±0.3 ml/min/100 mmHg, p= 0.35) between groups. Conclusion: These preliminary data suggest that patients with SCAD have greater increases in DBP and PP in response to mental stress compared to healthy controls. These exaggerated pressor responses might have implications for the pathophysiology of SCAD. NIH K23 HL155506, T32 DK07352, K01 HL148144, UL1 TR0022377, and AHA 898649. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.