The relationship between functional class, pulmonary artery pressure and size in left atrial myxoma

Copyright

0%7-2109(95)00090-9

Cardiovascular Surgery, Vol. 4, No. 3, pp. 320-323, 1996 0 1996 The International Society for Cardiovascular Surgery Published by Elsevier Science Ltd. Printed in Great Britain 0967-2109/96 $15.00 + 0.00

The relationship between functional class, pulmonary artery pressure and size in left atria1 myxoma T. Nakano, H. Mayumi, M. Hisahara, H. Yasui and K. Tokunaga Division of Cardiovascular Surgem ResearchInstitute of Angiocardiology; Faculty of Medicine, Kyushu UniversiQ Fukuoka, Japan To examine the correlation between the size of left atrial myxoma. the degree of pulmonary hypertension and the patient’s New York Heart Association (NYHA) functional class, the records of 29 surgically treated patients with left atrial myxoma were reviewed. Of 29 patients, 23 were catheterized before surgery. As the preoperative NYHA functional class advanced, the preoperative mean pulmonary artery pressure (mmHg) was seen to increase. Moreover, the weight of the excised myxoma also correlated well with the preoperative pulmonary artery pressure value. In five patients inserted with a Swan-Ganz catheter, the mean pulmonary artery pressure decreased immediately after tumour excision. Postoperatively, the average NYHA class of the 29 patients significantly improved. These results confirmed the positive correlation between the size of the tumour. the pulmonary artery pressure, and NYHA class in patients with left atrial myxoma. Copyright 0 1996 The International Society for Cardiovascular Surgery.

Keywords: cardiac tumour, pulmonary hypertension, heart failure, open heart surgery, left atrial myxoma

Patients with left atria1 myxoma manifest a variety of clinical features including anaemia, fever, weight loss, dyspnoea, congestive heart failure and shock, in addition to the normal features caused by tumour embolization’-‘. Moreover, deterioration of haemodynamics in these patients appears to result from left atria1 obstruction caused by the tumour. In fact, it is well known that both pulmonary hypertension and an elevation of pulmonary capillary wedge pressure exist in some patients with left atria1 myxomalW6. However, the exact correlation between the size of myxoma, degree of pulmonary hypertension, and patient’s NYHA functional class has not yet been clearly elucidated. Consequently, the records of 29 patients (catheterized preoperatively in 23 cases) with left atria1 myxoma were reviewed retrospectively at the authors’ institution; the data were then analysed to assessthe correlation of these factors.

Correspondence Surgery, Research Kyushu University,

Japan 320

to: Dr Institute 3-l-l

T. Nakano, Division of Cardiovascular of Angiocardiology, Faculty of Medicine, Maidashi, Higashi-ku, Fukuoka 812,

Patients and methods Patients Between 1972 and 1993, 29 patients with left atria1 myxoma (nine men and 20 women) were surgically treated at the authors’ institution. The mean(s.d.) age was .51.1(12.4) (range 21-73) years. Of these 29 patients, 23 who were catheterized preoperatively (79%) eventually entered the study. Since cardiac myxoma is currently diagnosed exclusively by echocardiography, six patients did not undergo preoperative cardiac catheterization. Pulmonary hypertension was defined as a systolic pulmonary artery pressure >40mmHg and/or a mean pulmonary artery pressure ~25 mmHg. Operative technique Tumour excision was successfully performed in all 29 patients under both cardiopulmonary bypass and cardioplegic arrest. In all cases, the left atria1 tumour had a stalk attached to the limbus of the fossa ovalis and was excised together with its attachment to the septum.

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6or-.------.----..--

The defect was closed directly or closed with the autologous pericardial patch. After excision, all cases were diagnosed pathologically as cardiac myxoma. The tumour weight (mean(s.d.) 36.8(22.2) (range 5.4-96.O)g) was recorded in 27 patients. Swan-Ganz catheters were inserted in five patients. The postoperative mean pulmonary artery pressure was measured in these patients at 88.0(27.1) min after termination of the cardiopulmonary bypass, and was compared with preoperative values.

-.

Data analysis All data were expressed as the mean(s.d.). Group data were compared by the Kruskal-Wallis test. When the variance was significant, Scheffe’s multiple comparison procedure was performed. The paired t-test was used when appropriate. To compare the incidence of the two groups, the x2 test with Yates’ correction was used. The correlation between the mean pulmonary artery pressure and tumour size was evaluated by a simple regression analysis. A P value co.05 was considered to be statistically significant.

0

20

40

excised

tumor

60

80

weight

(g)

100

Figure 1 Correlation between myxoma weight and mean pulmonary artery pressure by simple regression analysis.Mean pulrnc$nary artery pressure (PAP) is measured during preoperative cardiac catbetorization. Linear regression: y = 10.12 + 0.46x

The 29 patients with left atria1 myxoma were classified into four NYHA functional classes according to their preoperative exercise tolerance (Table 1). Among the 23 catheterized patients, pulmonary hypertension was seen in 14 patients (61%). The incidence of pulmonary hypertension, however, was more frequent among patients in NYHA classes III and IV than in those in class I (P = 0.034). The mean(s.d.) pulmonary artery pressure (mmHg) in classes I-IV was 12.8(2.3) (n = 4); 26.0(9.2) (n = 11); 33.5(9.6) (n = 4); and 45.6(6.2) (n = 4), respectively. The mean pulmonary artery pressure in class IV patients was significantly higher than that in

class I and II patients (P < 0.01). Similarly, the mean weight of the excised tumour in class IV patients was greater than that in class I and II patients (P < O.OOl), or that in class III patients (P < 0.01) (Table 1). A simple regression analysis confirmed a close correlation between the size of the excised tumour and the mean preoperative pulmonary artery pressure (P ~0.001) (Figure 1). Furthermore, in the five patients in whom a SwanGanz catheter was used, the mean(s.d.) pulmonary artery pressure fell from 34.6(8.7) to 18.4(3.9)mmHg (P c 0.01) soon after surgery (Figwe 2). The changes in NYHA functional class after excision of the left atria1 myxoma are shown in Eigurr 3. The

T&le

and the size of the left atrial myxoma

RawIts

1

Correlation

between

patients’

NYHA class. pulmonary

hypertension

NYHA functional I

II

No. of patients No. of preoperative catheterizations (%) No. of patients with pulmonary hypertension (% catheterized patients) Mean (sd.) pulmonary artery pressure (mmHg)

12.8 (2.3)

Mean

21.9

(s.d.)

weight

of excised tumour

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IV

Total

15

: (80) 0 (0)

(10.7)

*P < 0.05 compared with the NYHA class I group by the x2 test tP < 0.001 by the KruskaCWallis test among four NYHA groups. SP < 0.001 by the Kruskal-Wallis test among four NYHA groups. with the NYHA class Ill group by the Scheffe test. NYHA. New York Heart Association

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Ill

class

: (80) 4 (loo)*

f (100) 4 (loo)*

26.0 (9.2)

33.5 (9.6)

45.6 (62jt

29.6

40.8 (7.7)

74.0 (20.4)$

11 (73) 6 (55)

(16.0)

P c 0.001 compared P < 0.001 compared

;; (79) 14 (61) 28.4 (12.8) (II = 23) 36.8 (22.2) (n = 27)

with the NYHA class I and II groups by the Sci-teffe test. with NYHA class I and II groups. P c 0.001 compared

321

NYHA functional

class, pulmonary

artery pressure and atrial myoma:

50

8 2E

-

40

30

% a s Q)

E

20

10

* I%E Preop.

Postop.

Figure 2 Decrease in mean pulmonary artery pressure after tumour excision. *P =Z 0.01 (paired t-test). PAP. pulmonary artery pressure: Preop.. pulmonary artery pressure measured during preoperative cardiac catheterization: Postop.. pulmonary artery pressure measured by a Swan-Ganz catheter at 88.0(27.1) min (n = 5) after the termination of a cardiopulmonary bypass

n=2 n= n=2 n= n=2 n=13 is3 n=5 Preop.

Postop

Figure 3 Decrease in NYHA functional class after tumour excision. **P < 0.001 (paired t-test). NYHA. New York Heart Association: Preop., preoperative functional class: Postop.. functional class at the time of discharge

mean(s.d.) NYHA class in 27 patients improved from 2.3(0.9) to 1.2(0.4) at the time of discharge, the reduction being statistically significant (I’ < 0.001).

Discussion The clinical features of atria1 myxoma comprise haemodynamic deterioration, embolization and various constitutional manifestations. The haemodynamic deterioration in the patients with left atria1 myxoma occurs for two reasons. First, the pulmonary venous drainage decreasesdue to the left atria1 cavity being occupied by the tumour, or the orifice of the pulmonary veins being

7: Nakano et al.

directly obstructed. The rate at which myxoma grows in the left atrium remains unknown, though by reviewing the pathology of such large-sized tumours, it is possible to identify bleeding in the lesion which may result in rapid growth and, eventually acute obstruction or deterioration of normal haemodynamics in the left atrium. Second, mitral stenosis and/or regurgitation may occur as a result of an obstruction or a deformation of the mitral valve with the tumour3-‘. All these mechanismscome into effect even more dramatically as the tumour increases in size, and this correlation was clearly shown in the present study. When the excised tumour was large, the mean pulmonary artery pressure increased more and the functional status of the patients deteriorated even more severely, After tumour excision, moreover, the functional class of the patients clearly improved. In the two patients of NYHA class IV, huge myxomas were detected in the left atrium by echocardiography and severe pulmonary hypertension was revealed by preoperative cardiac catheterization. Both patients showed a rapid progression of congestive heart failure which resulted in multiple organ failure. Although an emergency operation dramatically improved the haemodynamic status in both cases, there was much controversy among cardiologists before surgery concerning the preoperative causes of severe pulmonary hypertension and heart failure. Generally, the clinical haemodynamics of left atria1 myxoma resemblethose of mitral valve disease2-‘. Foltz and co-workers’ described three sequential mechanisms which contribute to the pulmonary hypertension seenin patients with mitral valve disease:(i) a passive transmission of elevated left atria1 pressure and pulmonary venous pressure into the pulmonary artery; (ii) a reactive pulmonary arteriolar vasoconstriction; and (iii) morphologic changes in the pulmonary vasculature. The dramatic decrease in pulmonary artery pressure seen immediately after the excision of the tumour in most patients (Figure 2) may suggest that the first two mechanisms are usually important, while morphologic changes are rare in patients with left atria1 myxoma. In the two patients described earlier with severe pulmonary hypertension, however, a renewed increase in vasodilator dosage was required becauseof a re-elevation of the pulmonary artery pressure while in the intensive care unit. Hence, even though lung biopsies were not performed on patients with residual pulmonary hypertension, some morphologic changes in the pulmonary vasculature could occur in certain cases of left atria1 myxoma with chronic pulmonary hypertension.

Acknowledgements This work was supported by Grants-in-Aid for Scientific Research from the Ministry of Education, Science and Culture, and the Ministry of Health and Welfare, Japan.

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References 1. 2.

3. 4.

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Attar S, Lee YC, Singleton R et al. Cardiac myxoma. Ann Thorac Surg 1979; 29: 397-405. Peters MN, Hall RJ, Cooley DA, Leachman RD, Garcia E. The clinical svndrome of atrial mvxoma. IAMA 1974; 230: 695-701. ‘ Zitnik RS, Guiliasin ER. Clinical recognition of atria1 myxoma. Am Heart I 1970: 80: 689-700. Ghahramai AR,‘Arnold JR, Hildner FJ, Sommer LS, Samet l? Left atrial myxoma: hemodynamic and photocardiographic features. Am J Med 1972; 52: 52.5-32.

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Sung RJ, Ghahramani AR, Mallon SM et ai. Hemodynamic features of prolapsing and nonprolapsing left atria1 mvxoma. Circulation 197.5; 51: 342-9. Hanson EC, Gill CC. Razavi M et al. The surg~~l creatmrnt of atria1 myxoma. J Tborac Cardiovasc Swg 198 i; 89: 298-303. Foltz BD. Hessel EA. Ivev TD. The early course of nulmonarv artery hypertension in pa&nts u&q&g mitral valve replacement with cardioplegic arrest. J Thoruc Cnrdivxvrsi Sur,q 1984: 88: 238-47.

Paper

accepted

25 April

1995

323