Aim and methods
The study is the retrospective review of 184 patients with recurrent pericarditis referred to the Mayo Clinic in Rochester, Minnesota from 1994 to 2005, a major referral centre for pericardial diseases in the US. The clinical diagnosis of relapse was based on a prior diagnosis of acute pericarditis, subsequent recurrent chest pain, and one or more of the following signs: fever, pericardial friction rub, electrocardiographic changes, pericardial effusion on echocardiography, or pericardial inflammation on cardiac magnetic resonance imaging.
Of the analyzed 184 patients, 57 had undergone a complete pericardiectomy,1 patient had undergone a partial pericardiectomy (anterior phrenic to phrenic nerve and partial inferior pericardiectomy) at Mayo Clinic after failed medical management, and 126 patients continued with medical treatment only.
Pericardiectomy performed for relapsing pericarditis was as complete as possible. Pericardectomy entailed removal of the whole pericardium overlying the heart and great vessels except for the pericardium posterior to the left atrium in the oblique sinus. In standard practice, a small strip of pericardium remains beneath the phrenic nerves. Complete pericardiectomy can be difficult through a left anterolateral thoracotomy, and authors preferred a median sternotomy for most patients and began the operation with excision of the anterior portion of the pericardium from a point just anterior to the right phrenic nerve over the right ventricle and great vessels to a point just anterior to the left phrenic nerve. This portion of the procedure is facilitated by entering the pleural spaces early so that the phrenic nerve can be identified clearly and preserved. In contrast to pericardiectomy for chronic constrictive pericarditis, operation for relapsing pericarditis is usually simpler because of the absence of dense adhesions to the epicardium and because cardiac function is usually normal.
The primary follow-up outcome variables for both the surgically and medically treated groups were allcause death, time to relapse, and medication use for relapsing pericarditis.
Mean follow-up was 5.5 years in both groups (surgical vs. medical therapy). At baseline, patients in the surgical group had higher mean relapses (6.9 vs 5.5; P=0.01), were more likely to be taking colchicine (43.1% vs 18.3%; P=0.002) and corticosteroids (70.7% vs 42.1%;P<0.001), and were more likely to have undergone a prior pericardiotomy (27.6% vs 11.1%; P=0.003) than the medical treatment group. Perioperative mortality (0%) and major morbidity (3%) were minimal. Kaplan-Meier analysis revealed no differences in all-cause death at follow-up (P=0.26); however, the surgical group had a markedly decreased relapse rate compared with the medical treatment group (P=0.009). Five patients (8.6%) experienced relapse in the pericardiectomy group, while in the medical treatment group, 36 patients (28.6%) had a relapse after their index visit. Medication use was notably reduced after pericardiectomy.
This is the first study to compare pericardiectomy and medical management in patients with refractory relapsing pericarditis. Although it has been suggested that pericardiectomy should be considered in patients with severe relapsing pericarditis in whom an adequate drug treatment has failed, the evidence-based data to support this are few. In 1990, Fowler described 9 patients who underwent pericardiectomy for recurrent pericarditis, only 2 of whom showed clear-cut early improvement in symptoms. However, the course of follow-up and extent of surgical resection were not described (5). Also in 1990, Tuna and Danielson reported that 95% of patients who underwent a complete pericardiectomy for recurrent pericarditis were symptom free after 1 year with no operative or hospital deaths and argued that their favorable experience was attributable to the complete extent of the surgical resection of the pericardium (6). Both these studies are limited by small sample sizes, limited follow-up, and no comparisons with a medical treatment group. Since 1990, no other studies of adults undergoing pericardiectomy for relapsing pericarditis have been reported.
This study coming from a major tertiary referral centre (Mayo Clinic) from the US shows that pericardiectomy may offer positive results in selected patients with recurrent pericarditis.
However there are some limitations to be acknowledeged. This is retrospective study, and all the limitations of a retrospective analysis apply. The selection of treatment modality was mainly based on clinical assessment of the severity of disease and patient preference. During the time of patient recruitment from 1994 to 2005, several important articles were published that changed the clinical management of relapsing pericarditis (7-9). Thus contemporay optimal medical therapy may be lacking in some cases.
Mayo Clinic surgeons were experienced at performing pericardiectomy; morbidity and mortality rates for pericardiectomy may differ at less experienced centres. Current medical therapy for relapsing pericarditis, which includes NSAIDs, colchicine, corticosteroids, and immunosuppressive agents, is able to cure most patients with recurrent pericarditis.
However, there is still a group of patients who have refractory relapsing pericarditis. In this subset of patients, this study suggests that pericardiectomy is safe and effective at reducing subsequent relapses when compared with continued medical treatment only.
The authors suggest that optimal medical management remains the first-line treatment of relapsing pericarditis. However, if patients continue to have refractory recurrent symptoms and medical treatment has failed, especially when corticosteroids have been used for at least 6 months, they recommend that patients be considered for a pericardiectomy at an experienced surgical center.