Incidence, Impact and Mechanisms of Perioperative Right VEntricular Dysfunction (IMPRoVE)

A study to see how common right heart failure (right ventricular dysfunction) after major surgery is, and to investigate if right ventricular dysfunction causes worse patient outcomes after surgery.

Heart attacks are relatively rare around the time of surgery, however by measuring blood markers of heart injury, recent research has revealed that heart injury which otherwise may not be immediately obvious is common. Whilst this type of heart injury appears to be strongly linked to patient outcomes (complications, recovery and survival), the causes and potential treatments for it are not well understood.

Our research group has specialist knowledge about the right-hand side of the heart (right-heart) - the side that pumps blood through the lungs - which is less commonly considered or studied around the time of surgery. We have shown in previous studies using magnetic resonance imaging (MRI) scans (specialised whole-body scans which use a magnet rather than X-rays), evidence of right-heart function deteriorating after surgery. We want to test the idea that some of the blood marker evidence of heart injury reflects injury to the right-heart and more importantly that we can protect the right-heart around the time of surgery, reducing injury and improving patient outcomes.

We will examine these questions in the following ways:

1. With patients' permission, we will perform detailed ultrasound scans of the heart (echocardiography), and blood measurement of injury markers in 175 patients undergoing different types of major surgery. This will allow us to assess how common heart injury is (visible on scans of both sides of the heart), whether it makes any difference to a patient's outcome and whether it explains the changes seen in blood markers.
2. We will ask 50 of these patients to undergo MRI scans of the heart pre- and post-operatively to allow us to identify evidence of injury resulting from heart inflammation around the time of surgery. Inflammation is common following surgery and occurs throughout a patient's body - we believe heart inflammation may be responsible for postoperative heart injury.
3. In 10 of these patients, we will seek to obtain blood samples from vessels flowing into the heart (easily obtained from a simple blood sample) and from veins flowing out of the heart, obtained by passing a fine tube into the heart via blood vessels in a patient's neck under X-ray guidance. This will allow us to examine what happens to immune cells as they pass through the heart (i.e., are they activated by heart inflammation?) and better understand the meaning of the changes seen on MRI scans.

This study will give us a better understanding of which patients are likely to suffer heart injury around the time of surgery and how this injury occurs. With this knowledge, future patients could receive personalised treatment plans aimed at preventing injury and improving outcomes. We are not testing any new treatments in this study.

Eligibility Criteria:
Main echocardiography study

Inclusion Criteria:

1. Provision of informed consent
2. Age \>18 years
3. Planned elective primary hip or knee joint replacement under spinal anaesthesia, major colorectal, major vascular surgery or surgery requiring one lung ventilation with or without lung resection

Exclusion Criteria:

1. Pregnancy
2. On-going participation in any investigational research which could undermine the scientific basis of the study
3. Previous major surgery within three months prior to recruitment
4. Previous participation in the IMPRoVE study at any time
5. Inadequate comprehension of English resulting in inability to comply with instructions while undergoing investigations required for main study and sub-studies.

Additional exclusion criteria applicable to the T1 CMR sub-study includes:

1. Atrial fibrillation at baseline
2. Contraindication to cardiac magnetic resonance imaging (metal work in body etc)
3. Contraindication to IV Gadolinium: acute or chronic renal failure, allergy to contrast