Correlation Between Postoperative Blood Pressure Variability, Perfusion Index and Perioperative Adverse Events in Cardiac Surgery

Correlation Between Postoperative Blood Pressure Variability, Perfusion Index and Perioperative Adverse Events in Cardiac Surgery: A Single-Center Prospective Observational Cohort Study

In patients after cardiac surgery, disturbances in macrocirculatory fluctuations and tissue perfusion commonly coexist. The stress state induced by factors such as surgical manipulation, cardiopulmonary bypass, anesthetic agents, pain, and ischemia-reperfusion injury, along with the use of vasoactive drugs postoperatively, often leads to increased blood pressure fluctuations in the early postoperative period. Additionally, dysregulation of organ blood flow autoregulation post-surgery contributes to peripheral circulatory impairment, rendering perfusion pressure an unreliable indicator of actual organ perfusion. We aim to assess postoperative blood pressure fluctuation using blood pressure variability and evaluate peripheral circulatory status via the perfusion index. In this prospective cohort study, we will examine the correlation between these two parameters and perioperative adverse events.

Study Overview

• Status: Not yet recruiting
• Conditions: Hemodynamics; Cardiac Surgery Intensive Care Treatment
• Intervention / Treatment: Other: Blood Pressure Variability and Perfusion Index

• Study Type: Observational
• Enrollment (Estimated): 1200

Contacts and Locations

• Study Contact: Name: Nan Liu Director of the Center for Cardiac Intensive Care, MD, PhD; Phone Number: +8613370103573; Email: ln9102@126.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients undergoing cardiac surgery at Beijing Anzhen Hospital, Capital Medical University

Description

Inclusion Criteria:

• Age at surgery ≥ 18 years

  • Patients admitted to the ICU for the first time after undergoing their first cardiac surgical procedure during the current hospitalization ③ Expected to receive continuous invasive blood pressure monitoring and noninvasive pulse oximetry monitoring for at least 12 hours postoperatively in the ICU ④ Written or verbal informed consent obtained from the patient or their family members

Exclusion Criteria:

• Patients with severe peripheral vascular disease in the arm used for noninvasive pulse oximetry monitoring

  • Patients not undergoing invasive hemodynamic monitoring ③ Patients requiring preoperative or intraoperative support with IABP or ECMO

    • Patients expected to have incomplete postoperative monitoring data or a monitoring duration of less than 12 hours

      • Postoperative patients who are not admitted to the ICU for the first time during the current hospitalization ⑥ Patients admitted to the ICU prior to undergoing cardiac surgery ⑦ Patients with critically insufficient baseline preoperative data

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Adult Patients After Cardiac Surgery	Other: Blood Pressure Variability and Perfusion Index; All patients in this cohort will undergo invasive hemodynamic monitoring and noninvasive pulse oximetry, postoperative 24-hour blood pressure variability (from minute-to-minute invasive arterial pressure data) and perfusion index (from half-hourly recordings) were obtained through these monitoring modalities.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of the composite endpoint of adverse events within 30 days postoperatively	Total incidence of death, stroke, perioperative myocardial infarction, infection, reoperation, and continuous renal replacement therapy. Diagnostic criteria: Stroke was characterized by a new focal deficit associated with a compatible image on computed tomography. Perioperative myocardial infarction was diagnosed when cardiac troponin I shows an acute change with at least one value exceeding the 99th percentile upper reference limit, along with one of the following: new pathologic Q waves, imaging evidence of coronary artery occlusion, or imaging evidence of new loss of viable myocardium. Infection was considered if one of the following diagnoses was made by an Infectious Disease specialist who followed specific protocols: 1) Pneumonia; 2) Catheter related blood stream infection; 3) Sternal wound infection or osteomyelitis.	Within 30 days after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of low cardiac output syndrome within 30 days postoperatively.	Diagnostic criteria: Cardiac index < 2.0 L/min/m².	Within 30 days after surgery
Incidence of acute kidney injury within 30 days postoperatively.	Diagnostic criteria are based on the KDIGO guidelines.	Within 30 days after surgery
Incidence of acute respiratory distress syndrome within 30 days postoperatively	Diagnostic criteria are based on the 2012 Berlin definition of ARDS.	Within 30 days after surgery
Incidence of new-onset atrial arrhythmias within 30 days postoperatively.	Diagnostic criteria: atrial fibrillation or atrial flutter lasting more than 1 hour on continuous electrocardiographic monitoring, requiring pharmacological or electrical cardioversion.	Within 30 days after surgery
Incidence of prolonged ventilation (>24 hours) within 30 days postoperatively.		Within 30 days after surgery
Length of intensive care unit stay		Within 30 days after surgery

Collaborators and Investigators

• Sponsor: Beijing Anzhen Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2026
• Primary Completion (Estimated): June 30, 2026
• Study Completion (Estimated): August 1, 2026

Study Registration Dates

• First Submitted: December 19, 2025
• First Submitted That Met QC Criteria: December 19, 2025
• First Posted (Actual): January 5, 2026

Study Record Updates

• Last Update Posted (Actual): January 5, 2026
• Last Update Submitted That Met QC Criteria: December 19, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Cardiac Surgery; Blood Pressure Variability; Perfusion Index
• Other Study ID Numbers: KS2025145

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No