Discussion
Percutaneous hemodynamic support with Impella CP (Abiomed, Danvers, MA) support during PVI/PWI to the best of our knowledge has not been reported in the literature. Pubmed search did not yield case reports where Impella CP was used for hemodynamic support during PVI/PWI. Mantini et al. 2019 reported five series of patients with atrial arrhythmias who underwent various ablation techniques under various mechanical circulatory support (MCS) modalities. The MCS modalities included ECMO, LVADs, and Impella support. However, the only patient in their case report who had atrial fibrillation was cannulated for ECMO and AV node ablation, and pacemaker insertion is done (2). In a similar case report by Kamada et al. 2016, they described a case of tachycardia-induced cardiomyopathy secondary to persistent AF/RVR refractory to rhythm control both pharmacologically and electrically. However, PVI successfully achieved, intra-aortic balloon for MCS was only used after intra-procedurally (3) the patient became hemodynamically unstable. In contrast, our patient had Impella CP at the start of the procedure. Cheruvu et al. 2014, also reported on a successful ablation of refractory AVNRT in a patient on ECMO due to cardiogenic shock (4).
To date, there are no ACC/AHA/HRS/EHRA recommendations regarding PVIs or atrial arrhythmia ablations on MCS.
Most of the literature on mechanical support with Impella has been centered around its use in hemodynamically unstable ventricular tachycardia ablations. Activation and entrainment mapping techniques during ablation of ventricular tachycardias requires the patient to be in continuous VT, which may not be hemodynamically tolerated, may lead to end-organ hypoperfusion and damage(5,6). The use of left ventricular support provides a better augmentation of cardiac output during ablation for ventricular arrhythmias in at-risk patients.
In our article, we report on a 61-year-old male who developed cardiogenic shock due to tachycardia-induced cardiomyopathy due to persistent AF/RVR complicated by the cardiorenal syndrome. AF was both medically and electrically refractory, PVI under Impella support was pursued. There was instantaneous LVEF recovery, improvement in the RV function, and reversal of resultant end-organ failure.
Animal models have shown that, at the cellular level, high ventricular rates usually result in abnormal calcium handling and reduced energy-storing required for both myocardial relaxation and contractility (7). Changes at the cellular level lead to myocyte elongation, myofibril disorganization, and derangement in the extracellular matrix (7,8).
Over time, LV dysfunction occurs with LV dilatation and eventually RV failure and RV dilation. RV and LV volumes increase, LVEDP significantly increases due to the increase in LV wall stress(7–9). The loss of atrial contribution to diastole in a patient with AF/RVR, especially in patients with Grade 2 diastolic dysfunction leads to elevation of the left atrial volume and pressure, decrease preload and further decrease cardiac output(10). For all of these reasons, patients with AF/RVR can present with cardiogenic shock.
To reverse this spiraling cycle of myocardial dysfunction and heart failure symptoms for patients in AF/RVR, the CASTLE AF trial, which randomized 398 patients to PVI versus standard care, which included maintenance of sinus rhythm. The result showed about a 38% reduction in the primary outcome of all-cause mortality and hospitalization for worsening heart failure (11). CAMTAF Trial reached a similar conclusion, that catheter ablation is effective in restoring sinus rhythm in patients with persistent AF and HF(12).
Atrioventricular junctional ablation with biventricular pacing (AVJA/BiV) in patients with non-ischemic cardiomyopathy is useful for treating AF/RVR associated with HF(1).
However, Khan et al. in 2008 conducted the PABA-CHF trial, where they assigned NYHA II or III heart failure patients with drug-refractory AF and EF less than 40% to undergo PVI or AVJA/BiV. They conclude at the end of the trial that PVI was superior to AVJA/BiV in the following outcomes: freedom for atrial fibrillation, EF recovery, LA size, functional capacity and quality of life(13)
The utilization of the Impella device for circulatory support for mapping ventricular arrhythmias have been well published. (5,6)
Due to the effectiveness of PVI/PWI in patients with tachycardia-induced cardiomyopathy and cardiogenic shock, the Impella CP can be considered an effective MCS to provide hemodynamic stability during mapping and ablation of atrial arrhythmias not only limited to AF/RVR.
The use of the Impella allows time for accurate mapping in the case of atrial re-entrants tachycardia. For PVI/PWI, it allows adequate time for exit block testing and also posterior wall isolation with radiofrequency ablation after the cryoablation of the pulmonary vein ostia. It frees the operator’s mind to do thorough mapping and ablation with the knowledge that the patient is receiving adjustable support based on hemodynamic demands during the procedure.
Its use in electrophysiology laboratories is gaining popularity but for ventricular arrhythmia ablations for now. However, this case report is purposed to raise the awareness of the Impella’s utility advanced HF. Mainly in cases where ablative techniques are required to achieve hemodynamic stability in HF patients for which the atrial arrhythmia has been determined to be contributing significantly to the patient’s deterioration and hemodynamic instability.