Introduction
At present, over 15 million people are living with heart failure in
Europe. Heart failure is responsible in most westernized economies for
1-2% of all healthcare expenditures and is the leading cause of
hospitalization in people over the age of 65. The prognosis for HF
patients has remained alarmingly poor over the last twenty years.
Despite some notable improvements in survival rates, approximately 1 in
3 patients admitted to a hospital with HF still die within one year.
This places a huge financial burden on the health care system and
signals the typical downward spiral of the course of this disease. Due
to this fact, there has been a significant paradigm shift in the focus
of cardiac treatment worldwide in last two decades.
It has been common knowledge since the pivotal report by White et al.
that left ventricular (LV) chamber size is the single most important
metric in determining survival post myocardial infarction (MI). Ischemic
cardiomyopathy is a disease process wherein the patient develops HF due
to scar formation and subsequent LV enlargement. Ischemic cardiomyopathy
is the largest cause of HF, comprising approximately two-thirds of all
the 22 million HF patients worldwide. Analysis of the 10-year survival
of these patients based on LV size demonstrates the rapid divergence in
death rate in the initial several years. Hence, developing a safe and
effective approach for volume reduction in this most vulnerable patient
segment is the significant challenge in modern cardiac care.
Ischemic cardiomyopathy is frequently associated with LV scarring where
viable heart tissue has been damaged and is replaced by fibrotic scar,
which results in left ventricular dysfunction. The loss in left
ventricular function most often results in angina, significant dyspnoea,
ventricular arrhythmias, and an increased risk of thromboembolism and
death.
Surgical treatment is an option in advanced HF. Patients with
significantly enlarged LV end-systolic and end-diastolic volume indices
(LVESVI and LVEDVI) appear to benefit most from surgical intervention.
Relative contraindications to surgery include excessive anaesthetic
risk, impaired function of residual myocardium, severely diminished
cardiac index, and lack of a discrete scar with indistinct margins. Left
ventricular surgical treatment usually requires a median sternotomy,
cardiopulmonary bypass, and left ventriculotomy on either a beating or
arrested heart. Adoption of the surgical technique for correction of
this condition has been limited by both the invasiveness of the
procedure and potential for significant subsequent perioperative
morbidity and mortality. BioVentrix™ has developed the Revivent TC™
System to provide devices for the treatment of a left ventricular scar,
utilizing a less invasive, beating heart approach.
Less Invasive Ventricular Enhancement (LIVE) procedure with Revivent TC™
reshapes and resizes LV without sternotomy or extracorporeal circulation
through direct plication of the scarred myocardium. The procedure
consists in the implantation of a series of internal (right ventricular
septum) and external titanium microanchors (5 mm × 25 mm) which are
brought together through a poly-ether-ether-ketone (PEEK) tether (1.7 mm
× 1.0 mm) to approximate LV free wall and the anterior septum,
consequently excluding the scarred myocardium. Septal RV anchors are
deployed by a transcatheter technique, through a venous access on the
neck – right internal jugular vein.
First-in-human LIVE procedures were performed in September 2013. Since
the device obtained CE mark approval in June 2016, the multicentric
observational BioVentrix™ Registry Assessment of Ventricular Enhancement
for the Revivent TC™ system (BRAVE-TC) trial has been ongoing in Europe
(1).
In total, 230 cases have been performed with an overall mortality of 18
(7.8%). 12 cases of mortality occurred during the CE mark trial and 4
prior to changing the procedure to apical snaring (described below).
One-year results of a multicentric study were recently published by
Klein et al. (2), including 86 patients treated with Revivent TC™ system
has registered a significant improvement in LV ejection fraction (29 ±
8% vs 34 ± 9%, p<0.005) and an important reduction of LV
volumes - LV end-systolic and end-diastolic volume indexes (LVESVi and
LVEDVi) both decreased: 74 ± 28 mL/m2 vs 54 ± 23
mL/m2, p<0.001 and 106 ± 33
mL/m2 vs 80±26mL/m2, respectively,
p<0.0001. Mortality was 4.5% (4 patients) and 12-months
survival was 90.6%. There was also a documented clinical improvement of
the treated patients. This is the largest series of patients submitted
to LIVE therapy published so far.
In another series of 26 patients submitted to the LIVE™ therapy (3),
meaningful LV reduction was achieved - LVSEVi went from 84.8 ± 25.7 to
65.6 ± 24.4 ml/m2 and LVEDVi went from 107.8 ± 33.2 to
90.5 ± 31.8 ml/m2, both p<0.001
(Figure 1 ). Additionally, ejection fraction improvement was
observed by CMR: 28.9 ± 8.3% vs 38.6 ± 10.5%, p<0.001. There
was one mortality case reported. Lastly, also the 6-minute walk test was
significantly longer (368.8 ± 40.0 to 461.5 ± 61.2 m, p
<0.001), endorsing clinical benefit with the technique.
Between July 2018 and January 2020, 47 patients (84.4% men; mean age 61
± 12.5 years) were submitted to the LIVE procedure in 16 Institutions in
Europe, North America and Asia. Procedural success was 100%. There was
no intra-hospital mortality. There was no case of ventricular septal
defect, right ventricular perforation or sternotomy conversion. New
onset tricuspid valve regurgitation was observed in one patient. In the
mean follow-up period of 9.8 months, NYHA class improved a median of 1
grade and there was no late mortality.
We present this approach here, describing it step-by-step.