The combined effect of subcutaneous granulocyte- colony stimulating factor and myocardial contrast echocardiography with intravenous infusion of sulfur hexafluoride on post-infarction left ventricular function, the RIGENERA 2.0 trial: study protocol for a randomized controlled trial

Background Several clinical trials and recent meta-analyses have demonstrated that administration of recombinant human granulocyte-colony stimulating factor (G-CSF) is safe and, only in patients with large acute myocardial infarction (AMI), is associated with an improvement in left ventricular ejection fraction. Moreover, the mobilization and engraftment of the bone marrow-derived cells may differ significantly among patients, interfering with the restoration of left ventricular function after treatment. Therefore, the clinical potential application of the G-CSF has not yet been fully elucidated. Methods/Design The RIGENERA 2.0 trial is a multicenter, phase II, placebo-controlled, randomized, open-label, with blinded evaluation of endpoints (PROBE) trial in which 120 patients with an acute ST-elevation myocardial infarction (STEMI) undergoing successful revascularization but with residual myocardial dysfunction will be enrolled. In cases where there is a left ventricular ejection fraction (LVEF) ≤45 % the patient will be electronically randomized (1:1 ratio) to receive either subcutaneous recombinant human G-CSF (group 1) or placebo (group 2) both added on top of optimal standard of care. Both groups will undergo myocardial contrast echocardiography with intravenous infusion of sulfur hexafluoride (MCE) whilst undergoing the echocardiogram. The primary efficacy endpoint is the evaluation of the LVEF at 6 months after AMI assessed by cardiac magnetic resonance. Secondary efficacy endpoints are the evaluation of LVEF at 6 months after AMI assessed by echocardiography, left ventricular end-diastolic volume (LVEDV) and left ventricular end-systolic volume (LVESV) assessed by cardiac magnetic resonance and echocardiography at 6 months, together with the incidence of major adverse clinical events (MACE) defined as death, myocardial infarction, sustained cardiac arrhythmias, cardiogenic shock, stroke and re-hospitalization due to heart failure at 1 year. Discussion The RIGENERA 2.0 trial will test whether G-CSF administration and MCE, through the enhancement of the bone marrow-derived cells homing in the myocardium, determines an improvement in regional and global contractile function, myocardial perfusion and infarct extension in patients with large AMI. The results of the present study are expected to envision routine clinical use of this safe, affordable and reproducible approach in patients with successful revascularization after AMI. Trial registration ClinicalTrials.gov: NCT02502747 (29 June 2015); EudraCT: 2015-002189-21 (10 July 2015). Electronic supplementary material The online version of this article (doi:10.1186/s13063-016-1172-0) contains supplementary material, which is available to authorized users.


Medical history / demographics
A complete medical history will be obtained from each patient at the screening visit. Demographics, including gender, age and ethnic origin, and the smoking status will be recorded.

Killip Class
Patients will be ranked according to the Killip Class status. Definitions of the grading system are as follows: Class I: Absence of rales over the lung fields and absence of S3. No heart failure. No clinical signs of decompensation.
Class II: Rales over 50% or less of the lung fields or the presence of an S3. Heart failure.
Diagnostic criteria include rales, S3 gallop and venous hypertension.
Class III: Rales over more than 50% of the lung fields. Severe heart failure. Frank pulmonary edema.
Class IV: Cardiogenic shock. Hypotension (a systolic blood pressure of less than 90 mmHg for at least 30 minutes or the need for supportive measures to maintain a systolic blood pressure of greater than or equal to 90 mmHg), end-organ hypoperfusion (cool extremities or a urine output of less than 30 ml/h, and a heart rate of greater than or equal to 60 beats per minute). The hemodynamic criteria are a cardiac index of no more than 2.2 l/min per square meter of body-surface area and a pulmonary capillary wedge pressure of at least 15 mmHg. Signs include hypotension (systolic pressure < 90 mm Hg) and evidence of peripheral vasoconstriction such as oliguria, cyanosis and diaphoresis. Heart failure, often with pulmonary oedema, has also been present in the majority of these patients.

Physical examination
All patients will undergo standard or abbreviated physical examinations. The standard examination is based on the following body systems: body temperature, HEENT (head, eyes, ears, nose, throat), respiratory system, cardiovascular system, abdomen, extremities, neurological system. The abbreviated physical examination consists of body temperature, respiratory system, cardiovascular system, and lymph nodes. The body weight will be determined at each physical examination. The body height will be obtained at screening only.

Vital signs
Blood pressure and heart rate at rest will be determined using a standard method.

Electrocardiography
A 12 lead electrocardiogram (ECG) will be recorded. ECGs will be recorded while the patient is resting in supine position. Abnormal findings in ECG recordings will be documented and the clinical relevance will be judged. A de-identified copy of the baseline ECG will be digitally stored.

Clinical laboratory
Blood sampling and sample analysis will be performed at the clinical centre. The local investigator is responsible for proper judgment of abnormal blood test results, and is responsible for appropriate patient care following clinically significant pathological results. Please refer to section 6.4.5 to determine whether an abnormal laboratory value may constitute an adverse event.