Despite substantial advances in heart failure (HF) management, a significant number of patients progress to advanced HF, where medical therapy alone cannot prevent functional decline, multi-organ failure, or death. Although heart transplantation (HTx) is the treatment of choice for these cases, limited donor availability, comorbidities, or other contraindications restrict access for many patients. Fortunately, long-term ventricular assist devices (LT-VADs) have rapidly advanced in recent years, providing circulatory support to advanced HF patients in various situations. Eligible candidates for these devices may include those on the HTx waiting list (bridge to transplant [BTT]), patients requiring time to overcome a potentially reversible contraindication to HTx (bridge to candidacy), patients with the potential for myocardial recovery (bridge to recovery), or as destination therapy for those ineligible for HTx.
The objective of this study was to analyze the clinical characteristics, outcomes, and complications of all patients who received a LT-VAD in Spain from 2007 to 2020, utilizing data from the Spanish Registry of LT-VADs (REGALAD). During this period, a total of 263 LT-VADs were implanted across 22 Spanish hospitals with ventricular assist programs. Of these devices, 69% were continuous-flow left ventricular assists, while 30% were pulsatile-flow devices (58 left and 21 biventricular). Additionally, two cases involved a total artificial heart (1%). Regarding assist strategies, BTT was used in 78 patients (30%), bridge to candidacy in 110 patients (42%), bridge to recovery in 3 patients (1%), and destination therapy in 72 patients (27%). Overall survival at 6, 12, and 24 months was 79%, 74%, and 69%, respectively, with the best outcomes seen in patients with continuous-flow left ventricular assists (84%, 80%, and 75%, respectively). The main complications included infections (37% of patients), bleeding (35%), neurological events (29%), and device malfunction (17%).
The authors conclude that LT-VADs have become established in Spain as a valuable treatment for advanced HF, with a clear trend toward intracorporeal left continuous-flow devices, which are associated with better outcomes.
COMMENTARY:
This study is unique and highly relevant for Spain as it presents, for the first time, the characteristics and outcomes of each LT-VAD procedure performed in the country since the devices’ introduction.
Similar to other international registries, the total number of devices has progressively increased, though with a notable difference: our annual figures are significantly lower than those of other countries. For instance, if compared with 2019 INTERMACS registry data, Spain records 10 times fewer LT-VAD implants than the United States. Potential reasons for this disparity could include the relatively rapid access to HTx in Spain and differences in healthcare funding and budget allocations. Additionally, a high percentage of these transplants are conducted urgently under short-term mechanical circulatory support, reducing the use of LT-VADs as BTT. A further reason for the limited adoption of LT-VADs in Spain may be the lack of awareness about this treatment and its outcomes, resulting in fewer candidate referrals to specialized centers. Finally, the absence of favorable cost-effectiveness results also hinders LT-VAD expansion as a destination therapy within Spain’s public healthcare system.
Another striking difference between the REGALAD registry and others is the low incidence of severe INTERMACS profiles 1 or 2, at just 21% compared to 51% in the U.S. registry. In Spain, as recommended by the European Society of Cardiology’s latest HF guidelines, there appears to be an initial preference for short-term ventricular support in these critical patients as a bridge to LT-VADs (bridge-to-bridge strategy). Indeed, 8% of our registry patients had temporary mechanical support, with outcomes equally favorable to other registry patients.
Over the years, another significant change is the shift from pulsatile paracorporeal devices to smaller, continuous-flow intracorporeal devices, which have a lower complication rate, lower energy consumption, and greater durability. The HeartMate 3 has been predominant in recent years and will likely remain so, as the other market alternative (HVAD, HeartWare) ceased distribution in June 2021 due to higher adverse event rates.
Overall survival, at 74% and 69% at 1 and 2 years, respectively, is similar to that reported in other international registries. However, these outcomes are partially hindered by a high percentage of pulsatile-flow and biventricular assists, as well as the participation of centers with limited experience. Nonetheless, the strong survival rates of isolated continuous-flow left ventricular LT-VADs, at 80% at 1 year and 75% at 2 years, are almost identical to those in the INTERMACS registry.
Notably, we found no significant differences in survival across implantation objectives, unlike other registries, where BTT or bridge to candidacy patients, who are generally younger with fewer comorbidities, show better outcomes than destination therapy patients. Although the proportion of destination therapy patients in the REGALAD registry is increasing, it remains significantly lower than in the INTERMACS registry, which reached 78% in 2020.
Complications remain frequent and serious, representing the primary barrier to broader treatment adoption. Stroke, both ischemic and hemorrhagic, is the leading cause of death, accounting for 38% of cases. Strict control of risk factors, especially blood pressure, as well as the development of more hemocompatible LT-VADs, is expected to reduce the incidence of this severe complication. Device dysfunction, particularly pump thrombosis, more common in pulsatile paracorporeal pumps, has fortunately decreased over time. Preventing thromboembolic events with dual antithrombotic therapy partly contributes to bleeding events, particularly gastrointestinal hemorrhage (19% in this series). Infections are another common complication, particularly those related to the percutaneous drive cable in intracorporeal devices. These infections are challenging to eradicate and necessitate prolonged antibiotic therapy, adversely affecting patients’ quality of life. Fortunately, newer devices show a downward trend in these complications.
The main limitation of this registry, compared with others, is the small sample size and relatively short follow-up duration.
Technological advancements in increasingly effective and safer mechanical devices promise a bright future in the field of LT-VADs, likely revolutionizing advanced HF therapy in the near term. So far, as demonstrated by the REGALAD registry, LT-VADs have established themselves as a viable treatment for selected advanced HF cases in Spain, with continuous-flow intracorporeal left ventricular devices proving highly effective for this devastating condition. Although there is still much progress to be made before reaching the LT-VAD usage rates seen in other developed countries, the excellent outcomes presented in the REGALAD registry, comparable to those in other international registries, highlight the capabilities of mechanical circulatory assist programs in Spain. Without a doubt, this paves the way for the expected expansion of these devices within the Spanish National Health System in the coming years.
REFERENCE
Gómez-Bueno M, Pérez de la Sota E, Forteza Gil A, Ortiz-Berbel D, Castrodeza J, García-Cosío Carmena MD, et al. Durable ventricular assist device in Spain (2007-2020). First report of the REGALAD registry. Rev Esp Cardiol (Engl Ed). 2023 Apr;76(4):227-237. English, Spanish. doi: 10.1016/j.rec.2022.07.011.
