Primary cardiac tumors are rare. Roughly 75% of cardiac tumors are benign; half of these are myxomas, which have an approximate incidence of 0.5-1.0 cases per million inhabitants per year. Myxomas occur in all age groups and in both sexes, although they occur more often in women between the third and sixth decades of life.1)2)

Although histologically benign, in some cases myxomas are lethal due to impaired cardiac dynamics and thromboembolic potential.3) When tumors are diagnosed and resected in a timely manner, they lose their deleterious potential and patients are cured, except for rare cases of recurrence.4)5) Patients have survival similar to that of a normal person, and there is no impact on quality of life.

With the availability of echocardiography among initial ancillary tests performed in cardiovascular practice, tumor detection has increased. This has resulted in increased publication of case reports and patient series on cardiac tumors.

There are few local reports describing the surgical outcome of these tumors.⁶⁾⁷⁾ In this study, we present the 20-year experience of our institution in diagnosis and long-term follow-up of patients with cardiac myxomas.

The goals of this study were to assess the clinical presentation of cardiac myxomas and their correlation with echocardiographic features and describe the perioperative results and long-term outcome of surgically treated patients.

The most important finding of our study was that 76.5% of villous myxomas presented with embolic episodes, whereas no embolic events occurred in patients with smooth surface myxomas. Smooth tumors are larger, occur with obstructive symptoms, and benefit from elective surgery, whereas villous myxomas entailed a high embolic risk and required urgent surgical treatment.

Primary cardiac tumors are a rare disorder; myxoma is the most frequent primary cardiac tumor. The sporadic type is seen most often and comprises about 93% of all varieties. Women are affected more often than men, and the average age of patients is approximately 50 years. Tumors are generally solitary, most often located in the left atrium, especially around the fossa ovalis, and their recurrence rate is minimal.1) The other subgroup of familial myxomas mainly affects young people, and female predominance is not as marked. These cases are part of an autosomal-dominant disease known as Carney Complex Syndrome.2)11)

In our series, the mean age at presentation was the fifth decade of life, and the slight predominance of women affected is in agreement with other published series.5)10)12)13)14)15)

As imaging methods have improved, in vivo diagnosis of myxomas has increased. In our study, 17% of cases were detected during a routine echo exam performed for other reasons or to evaluate patients with cardiovascular risk factors; this incidental diagnosis rate is similar to those of other series.12) These tumors were smaller than those found in symptomatic patients. Selkane et al.13) recently showed that smaller tumors were resected in patients who were older and had more comorbidities, probably because such patients are evaluated more thoroughly for other specific health problems.

Although histologically benign, these tumors can be lethal due to their location in the circulatory system. The predominant site of tumor implantation is the fossa ovalis of the septum in the left atrium, similar to that described in other local6)7) and international studies5)10)12)13)14)15); the frequency of valvular and biatrial tumors were also similar to reports in other studies.

Although clinical manifestations vary among studies, the classic presentation comprises a triad of symptoms (“myxoma triad”), which includes embolic and obstructive phenomena and constitutional symptoms. In our study, as in the study by Pinede et al.12), obstructive symptoms prevailed. Dyspnea was the most frequent complaint, evidenced by a high percentage of patients with signs of clinical heart failure. In the echocardiogram, these patients had a larger tumor diameter, greater valve obstruction, and pulmonary hypertension. Constitutional symptoms occurred in one-fourth of our patients, predominantly in larger tumors located in the left atrium, as described previously.12)15) The etiologies of constitutional manifestation are not fully understood. They may be related to embolization (facial edema, myalgia, arthralgia, and nocturnal hemoptysis), erythropoietin production (erythrocytosis), mechanical destruction of cells by abnormal blood flow across the tumor surface (thrombocytopenia, hemolytic anemia-particularly associated with calcified tumors),2) or autocrine production of cytokines such as IL6 and IL8 (inflammatory and autoimmune responses) accompanied by activation of the complement cascade by circulating antibody–tumor–antigen complexes.16)17)18)

Embolic manifestations are the most severe due to their morbidity and mortality; they are attributed to detachment of small friable tumor fragments. In our study, 76.5% of villous myxomas presented with embolic episodes, whereas no embolic events occurred in patients with smooth surface myxomas. All patients who had embolic events had tumors with villous appearance on echocardiography; no patients with smooth myxomas had embolic episodes, in concordance with previous series.10)19) Wang et al.5) also proved that small myxomas predict embolism. In our series, patients with embolic manifestations had a villous surface but there were no differences in tumor size, which could be explained by the lower number of patients in this study.

This highlights the importance of the echocardiogram in describing the morphologic characteristics of these tumors, which predicts patients at higher risk of having an embolic complication and those who may require surgery as soon as possible after diagnosis.

Heterogeneous intratumor appearance was not associated with cardiovascular events. Although histology showed a correlation with foci of calcification, it was not useful in predicting foci of necrosis or hemorrhage.

Since Craford20) performed the first surgery in a patient with a left atrial myxoma in 1954, several surgical techniques and safe approaches have been developed. In our study, the right atrial and transseptal approaches were used in most cases, and the left atrial tumor was resected through the atrial septum followed by simple closure. Currently, this technique is performed through a median sternotomy on cardiopulmonary bypass with prior aortic and bicaval cannulation and moderate hypothermia. Because it is safe and has very low mortality, it is the technique used most often.5)12)14)21)

In our series, 12% of patients underwent valve repair. Some problems encountered relate to the condition of the valve apparatus, degree of concomitant mitral or tricuspid regurgitation, and the need for resection with an adequate safety margin, which might explain the need for valve repair.

Although the time between diagnosis and surgery varies among studies, we have no evidence regarding the urgency for intervention. However, the consensus is that elective but urgent surgery should be performed within 48 to 72 hours.

Surgery is safe, and perioperative mortality is low. Although elderly patients with comorbidities were operated on, there were no deaths in the immediate postoperative period, and long-term survival was good. These findings differ from those for patients who were not operated on, who had the lowest rate of 10-year survival. This may confirm the need for surgery in these patients, regardless of their surgical risk.

Although there were no perioperative deaths, most patients had some complication. As with other local6)7) and international5)10)12)13)14)15) studies, arrhythmias were the most common complication. These were mainly supraventricular in origin and occurred in one-third of the patients.

Once the postoperative period is over, long-term prognosis is good, similar to that of normal subjects; this study showed an excellent 10-year survival rate of close to 90%.

Recurrence was quoted to be less than 5%,5)14)22)23) and although the familial form exhibits higher recurrence rates, it may also have occurred in sporadic forms. The cause of recurrence was unclear, although it was apparently due to growth of a remnant tumor focus that was not identified in the first surgery. Alternative hypotheses involve other mechanisms, such as spontaneous or perioperative intracardiac implantation and multicenter growth. Close echocardiographic follow-up is indicated for all operated myxomas to ensure early diagnosis and intervention in case of recurrence. This strategy allowed identification of tumor recurrence in a patient who did not have evidence of the familial form. He had initially undergone resection of a villous left atrial myxoma followed by simple closure of the septal resection. The second time, myxoma resection required a septal repair with a pericardial patch.