Clinical Research Directory

Post-Induction Low Cardiac Output Syndrome in Coronary Artery Bypass Graft Surgery

Hemodynamic change after induction of general anesthesia is usually judged from mean arterial pressure. Pressure, however, is a surrogate for flow, and the two can separate: cardiac output may fall while arterial pressure remains apparently adequate. The interval that follows induction of anesthesia, before surgical stimulation begins and while hemodynamic conditions are determined by anesthetic management alone, has not been characterized in terms of flow. This study is designed to define post-induction low cardiac output (PiLCOs) in patients undergoing coronary artery bypass grafting. This is a prospective, observational, two-centre cohort study. Consecutive adults undergoing isolated coronary artery bypass grafting with cardiopulmonary bypass at two tertiary cardiovascular surgery centre will be enrolled. No aspect of anesthetic or surgical management will be altered for the purposes of the study. An arterial catheter is sited before induction while the patient is awake, and cardiac index is recorded continuously at 30-second intervals by arterial waveform analysis. Mean arterial pressure, heart rate, stroke volume index and cardiac index are recorded at the same resolution. The analysis window is the 30 minutes that follow induction of anesthesia. The period of cardiopulmonary bypass is excluded from all analyses, because flow during bypass is generated by the pump rather than by the heart. The primary outcome has two components, both defined over that window and both referenced to a cardiac index threshold of 2.0 L/min/m2. The first is the total time spent below threshold, in minutes. The second is the cumulative low-output burden, defined as the integral over time of the difference between the threshold and the measured cardiac index, taken only where that difference is positive. Dimensional analysis reduces the unit of burden to L/m2, a body-surface-indexed volume of undelivered flow, which multiplied by body surface area yields an absolute flow deficit in liters. Time below threshold describes how long the exposure lasts and cumulative burden describes how deep it is. The two together define the exposure, and neither alone is sufficient. Secondary outcomes are the same two measures computed at cardiac index thresholds of 2.2 and 2.5 L/min/m2; the incidence of PiLCOs, defined as at least one measurement below 2.0 L/min/m2 within the window; the time-weighted average depth across the window and the median depth sustained while below threshold; the distribution of cumulative burden across the three consecutive ten-minute segments of the window; and the time from induction to the first measurement below threshold. Exploratory analyses will examine the association between the presence and the magnitude of PiLCOs and the postoperative course, including acute kidney injury, serum lactate, duration of mechanical ventilation, intensive care unit and hospital length of stay, and mortality. All outcome analyses are treated as exploratory and hypothesis-generating, and no adjustment is made for multiple comparisons. Sample size was derived from an internal pilot of 30 patients, comprising the first 15 consecutive patients enrolled at each centre. In that pilot the standard deviation of time below threshold was 8.14 min and the incidence of PiLCOs was 70.0%. Setting the half-width of the 95% confidence interval at 1.7 min for mean time below threshold requires 88 patients, and setting it at 9.5 percentage points for incidence requires 90; the larger figure was carried forward and rounded to 90, allocated as 45 patients per centre. Allowing 15% for withdrawal, protocol deviation and unusable recordings gives a planned enrollment of 104 patients. Because the study estimates the frequency and the magnitude of an event that has not previously been characterized, rather than testing a prespecified superiority hypothesis, sample size is based on the precision of estimation rather than on power.

Comparison of Allows Measurement of Cardiac Output Between Clearsight System and Transpulmonary Thermodilution

Correlation study between the data provided by two measurement systems, trans- pulmonary thermodilution and ClearSight © (non invasive), to determine the interest in routine use (cardiac output, cardiac index, stroke volume and blood pressure).

Correlation of Cardiac Index Measured by the PRAM Method With NIRS and Lactate Levels in Pediatric Aortic Coarctation Surgery

This prospective observational study aims to evaluate the correlation between cardiac index measured by the MostCare™ system (Pressure Recording Analytical Method, PRAM) and cerebral/renal regional oxygen saturation measured by near-infrared spectroscopy (NIRS) and arterial lactate levels in neonates and infants (body weight 2.5-3.5 kg, age 0-3 months) undergoing surgical repair of aortic coarctation. Measurements will be recorded at four intraoperative time points: after anesthesia induction, before aortic cross-clamp, 3 minutes after cross-clamp release, and at end of surgery. No additional intervention beyond standard anesthesia and surgical care will be applied.

Effect of Labetalol, Atenolol, and Nifedipine on Maternal Hemodynamics Measured by ICG in Early Pregnancy

The purpose of the research is to characterize the effect of labetalol, atenolol, and nifedipine on maternal hemodynamics early in pregnancy. Patients will be given medication based on their hemodynamics and asked to return for a repeat measurement.

COR-INSIGHT: Optimizing Cardiovascular and Cardiopulmonary Outcomes with AI-Driven Multiplexed Indications Using COR ECG Wearable

The COR-INSIGHT trial aims to evaluate the effectiveness of Peerbridge COR advanced ambulatory ECG wearables (COR 1.0 and COR 2.0) in accurately and non-invasively detecting cardiovascular and cardiopulmonary conditions using AI-based software (CardioMIND and CardioQSync). The study devices offer non-invasive, multiplexed, AI-enabled direct-from-ECG detection as a novel alternative to traditional diagnostic methods, including imaging, hemodynamic monitoring systems, catheter-based devices, and biochemical assays. Continuous COR ECG data collected in hospital, outpatient clinic, or home settings will be analyzed to evaluate the predictive accuracy, sensitivity, specificity, and performance of these devices in differentiating between screen-positive and screen-negative subjects. The panel of screened indications encompasses a broad spectrum of clinically relevant cardiovascular, cardiopulmonary, and sleep-related diagnostic parameters, which are critical for advanced patient assessment and management. In the cardiovascular domain, the protocol emphasizes the detection and classification of heart failure, assessment of ejection fraction severity, and identification of myocardial infarction, including pathological Q-waves and STEMI. It further addresses diagnostic markers for arrhythmogenic conditions such as QT interval prolongation, T-wave alternans, and ventricular tachycardia, as well as insights into ischemia, atrial enlargement, ventricular activation time, and heart rate turbulence. Additional parameters, such as heart rate variability, pacing efficacy, electrolyte imbalances, and structural abnormalities, including left ventricular hypertrophy, contribute to comprehensive cardiovascular risk stratification. In the non-invasive cardiopulmonary context, the protocol incorporates metrics like respiratory sinus arrhythmia, cardiac output, stroke volume, and stroke volume variability, providing critical insights into hemodynamic and autonomic function. The inclusion of direct-from-ECG metrics for sleep-related disorders, such as the apnea-hypopnea index, respiratory disturbance index, and oxygen saturation variability, underscores the protocol's utility in addressing the intersection of cardiopulmonary and sleep medicine. This multifaceted approach establishes a robust framework for precision diagnostics and holistic patient management. The COR 1.0 and COR 2.0 wearables provide multi-lead ECG recordings, with COR 2.0 offering extended capabilities for cardiopulmonary metrics and longer battery life (up to 14 days). COR 2.0 supports tri-modal operations: (i) Extended Holter Mode: Outputs Leads II and III, mirroring the functionality of COR 1.0 for broader ECG monitoring applications. (ii) Cardiopulmonary Mode: Adds real-time recording of Lead I, V2, respiratory impedance, and triaxial accelerometer outputs, providing advanced cardiopulmonary insights. (iii) Real-Time Streaming Mode: Streams data directly to mobile devices or computers via Bluetooth Low Energy (BLE), enabling real-time waveform rendering and analysis. The COR 2.0 units are experimental and not yet FDA-cleared. Primary endpoints include sensitivity (true positive rate) \> 80%, specificity (true negative rate) \> 90%, and statistical agreement with reference devices for cardiovascular, cardiopulmonary, and sleep metrics. Secondary endpoints focus on predictive values (PPV and NPV) and overall diagnostic performance. The study employs eight distinct sub-protocols (A through H) to address a variety of cardiovascular, cardiopulmonary, and sleep-related diagnostic goals. These sub-protocols are tailored to specific clinical endpoints, varying in duration (30 minutes to 14 days) and type of data collection. Up to 15,000 participants will be enrolled across multiple sub-protocols. Screening ensures eligibility, and subjects must provide informed consent before participation. Dropouts and non-compliant subjects will be excluded from final analyses.

Non-invasive Continuous Cardiac Output Monitoring in Preterm Infants Study

This is an observational study in newborn term and preterm infants. The study will validate if non-invasive continuous cardiac output monitoring is feasible in newborn infants, if normative values can be constructed and what is the effect of fluid boluses and inotropes on cardiac output and peripheral vascular resistance.

Evaluating Fluid Responsiveness in ICU Patients Using VTI and Trendelenburg Positioning

Fluid administration is a commonly performed in the ICU for critically ill patients. However, it can lead to complications such as fluid overload, pulmonary edema, and increased mortality in some patients. Therefore, identifying patients who are likely to respond to fluid therapy is crucial for optimizing their management. Several methods have been used to assess fluid responsiveness, such as passive leg raising, stroke volume variation, and cardiac output monitoring. However, these methods have limitations and may not be feasible in all patients. In this study, the investigators aim to evaluate the use of velocity time integral (VTI) and Trendelenburg positioning in predicting fluid responsiveness in ICU patients.