Br Heart J: first published as 10.1136/hrt.32.1.26 on 1 January 1970. Downloaded from British HeartJournal, 1970, 32, 26. Systemic embolism in mitral valve disease N. Coulshed, E. J. Epstein, C. S. McKendrick, R. W. Galloway, and E. Walker From Liverpool Regional Cardiac Centre, Sefton General Hospital, Liverpool I5 The analysis of a series of 839 cases of mitral valve disease has shown the following. (a) Systemic embolism is as common with mitral regurgitation as with mitral stenosis. (b) Atrialfibrillation, with clot formation in the atrium, is the main cause predisposing to systemic embolism. (c) Mitral valve calcification is important only in that it predisposes to operative emboli. (d) Atrial appendage size has no influence on the occurrence ofsystemic embolism, and atrial appendagectomy has no influence on the occurrence of post-operative embolism. (e) Only in patients with atrial fibrillation and an operable valve, is there any reduction in the number of emboli after surgery. Certain guide-lines with regard to treatment are suggested. Peripheral arterial embolization is a serious, has been undertaken, we have tried to evaluate sometimes fatal, complication of mitral valve its usefulness in the prevention of systemic and Bern- emboli. disease. Askey (I957) and Askey Of the 839 patients, 28 had systemic emboli stein (I960) state that a first recognized before coming under review, but each of these embolus is fatal in about one in six so affec- patients was known to have had mitral valve ted, and that one-half of the survivors die disease before the embolism, and in no case was within three years, half of these because of mitral valve disease recognized because of the recurrent embolism. Surgical measures de- occurrence of an embolus. For the purpose of signed to improve valve function, and to this review, those patients having had systemic http://heart.bmj.com/ remove potential sources of clot formation, embolism as a result of bacterial endocarditis have been advocated for the prevention of were excluded. are As judged by the usual criteria, i.e. clinical, this hazard. Among the many reports electrocardiographic, and radiological, 737 patients those of Madden (I949), Belcher and Somer- had predominant mitral stenosis, and I02 had ville (I955), Glover (I956), Turner and mitral regurgitation. This was an arbitrary divi- Fraser (1956), Ellis, Harken, and Black sion, and occasionally it was difficult to decide (I959), Baker and Hancock (i960), and which was the dominant lesion, but stenosis Learoyd et al. (I960). Kellogg et al. (I96I) was always considered the most important lesion on October 1, 2021 by guest. Protected copyright. and Taber and Lam (I960) emphasized the in those cases put forward for closed mitral possible hazards of emboli occurring at valvotomy. operation, but Ellis and Harken (I96I) in a In all, 74 patients (8 8°'%) had more than trivial their reasserted aortic valve disease, and 17 of these had closed further review of patients mitral and aortic valvotomy; 8 patients were found their belief in the protective value of mitral to have organic tricuspid valve disease, the diag- valvotomy against further emboli. They also nosis being based mainly on catheter findings, thought that where mitral stenosis was and in 3 of the 8, closed mitral and tricuspid present, the occurrence of a systemic embo- valvotomy was performed. lus was in itself an indication for operation. Results Subjects The total incidence of embolism is shown in This paper is based on 839 cases of rheumatic Table i for mitral stenosis and in Table 2 for mitral valve disease seen at the Liverpool Regional mitral regurgitation, with reference to the Cardiac Centre between I952 and i965. Where cardiac rhythm, the age of the patient, and follow-up was possible, assessments were made at disability graded according to the classifica- 6-monthly intervals by at least one of the authors. tion of the New York Heart Association We have attempted to study the incidence of arterial embolism, together with possible factors (I964). in its causation; and where cardiac operation In both groups, there is an increasing incidence of embolic episodes with increas- Received I6 January i969. ing age and with atrial fibrillation, but not Br Heart J: first published as 10.1136/hrt.32.1.26 on 1 January 1970. Downloaded from Systemic embolism in mitral valve disease 27 TABLE I Incidence of systemic emboli in 737 cases of mitral stenosis Diseility Sinus rhythm Atrialfibrillation and atrtalfibril- lation combined Age 35 and below Age 36 and above Age 35 and below Age 36 and above All ages Total Emboli Total Emboli Total Emboli Total Emboli Total Emboli cases cases cases cases cases 0, 1, 2 146 6 I28 17 32 10 158 64 464 97 3 4I 2 52 5 12 2 83 19 I88 28 4 I0 I 15 0 7 2 53 I2 85 I5 Totals 197 9 195 22 5I I4 294 95 737 140 TABLE 2 Incidence of systemic emboli in 102 cases of mitral regurgitation Disability Sinus rhythm grade Sinus rhythm Atrial fibrillation and atrialfibril- lation combined Age 35 and below Age 36 and above Age 35 and below Age 36 and above All ages Total Emboli Total Emboli Total Emboli Total Emboli Total Emboli cases cases cases cases cases 0, 1, 2 25 0 10 2 7 0 i6 3 58 5 3 I 0 I 0 5 I I6 6 23 7 4 I I I 0 7 2 I2 2 2I 5 Totals 27 I 12 2 19 3 44 II I02 I7 http://heart.bmj.com/ with a worsening disability. With dominant mitral valve disease were referred only after mitral stenosis, emboli occurred in 31 Out of a major embolus had occurred. Of the 28, 9 392 patients with sinus rhythm (8%), and were in sinus rhythm, and I9 in atrial fibril- in I09 Out of 345 with atrial fibrillation lation; 24 had a disability of grade 2 or less, (3I 5%). With dominant mitral regurgitation, and 4 were aged 35 or less. emboli occurred in 3 out of 39 patients with sinus rhythm (7 7%), and in 14 out of 63 Pre-operative emboli, atrial thrombus, with atrial fibrillation (22%). and atrial appendage size In most cases, on October 1, 2021 by guest. Protected copyright. The incidence of embolism is similar embolism must be related to the formation in both groups, and when considered to- of thrombus in the left atrium or ventricle, gether, the figures range from IO emboli in and certainly if clot is present it must increase 224 patients aged,35 or less in sinus rhythm the risk of producing emboli at operation. (4 4%)°, to Io6 emboli in 338 patients aged Unfortunately, a history of embolism does 36 or more with atrial fibrillation (3I 6%). not help in predicting the presence of clot QX the I57 patients with emboli, 32 (20%) discoverable at operation, since, in this were in sinus rhythm when examined. None present series, such clot was found in only of these patients gave a history of paroxysmal I7 of 114 patients where emboli had occur- dysrhythmia, though this diagnosis could red (i5%), and in 75 of 44o patients with not be excluded. It was not possible to no history of embolism (i7%). determine the rhythm at the time of em- It has been thought that the size of the bolization in I8 (II'5%), and I07 (68 i%) atrial appendage has a direct influence on were in atrial fibrillation when examined. the clot formation therein, and hence the Nine (5 8%) had the atrial fibrillation for risk of embolus formation, both before and less than one month, and 6o (38 I%) for during operation (Somerville and Cham- more than one month when embolization bers, I964). If this could be proved true, occurred. In 38 (24I%) it was not possible then it would be of considerable value both to determine the duration of the atrial fibril- prognostically and in the planning of opera- lation. tion. We have tried to elucidate this problem In all, 28 patients with known rheumatic by an attempted radiological assessment of Br Heart J: first published as 10.1136/hrt.32.1.26 on 1 January 1970. Downloaded from 28 Coulshed, Epstein, McKendrick, Galloway, and Walker the left atrial appendage size in two different TABLE 3 Incidence ofpre-operative groups of patients. embolism in all cases operated upon, cor- The radiological assessment of the left related with valve calcification and cardiac atrial appendage from a standardized 6-foot rhythm postero-anterior x-ray was accomplished with reference to an imaginary line drawn from Rhythm I Pre-operative embolism No pre-operative embolism the left border of the aortic knuckle to the cardiac apex. Thus, grade o is where no Calcification Calcification Calcification Calcification present absent present absent atrial appendage shadow can be seen, grade I is where the appendage is visible on the Sinus 10 II 8i I83 left cardiac border but does not extend Atrial closer than 2 mm. to this line, grade 2 is fibrillation 37 56 78 98 where the left border ofthe appendage shadow lies from 2 mm. medial to 7 mm. lateral to the line, while grade 3 is where the appen- dage shadow extends beyond the lateral mitral stenosis and those cases in which was limits of grade 2, and often has a separate exploratory cardiotomy performed. was out on outline of its own. Operation carried 206 patients Pre-operative x-rays were assessed in 104 with valve calcification, 47 having had pre- patients known to have had systemic emboli, operative emboli (23%); 348 patients with- out calcification included who had and 53 were found to have an atrial appendage valve 67 suffered pre-operative emboli (:i%).