Cardiac Rupture in Patients with Acute Myocardial Infarction

Cardiac Rupture in Patients with Acute Myocardiallnfarction* I. Shapira, M.D.; A Isakoo, M.D.; M. Burke, M.B.B.S.; and Ch. Almog, M.D., F.C.C.P.

The eeearrence of myocardial rupture was evaluated in an unselected population of 1,737 patieDts with acute myocardial infarction (AMI). Patients with cardiac rupture after AMI were compared with age- and sex-matched control patieDts with fatal AMI not related to rupture and with AMI survivors discharged home. Rupture was found in 40 patieDts (15.7 percent of hospital deaths~ or 1.3 percent of all cases of AMI. At the highest risk for rupture were women aged 60 to 69, although the age distribution di~ Dot differ significantly from that of patients dying of other causes. More patients with myocardial rupture had hypertension

during hospitalization, penistent pain, and inferior wall myocardial infarction when compared with controls. The majority (95 percent) of cardiac ruptures occurred within the 6nt six days, 40 percent within the 6rst S4 hours after the onset of symptoms. Approximately 20 percent of ruptures were diagnosed as subacute; in only two was surgical interventioD attempted unsuccessfully. 11le high-risk group of patients should be carefully monitored within the 6nt six days after the onset of symptoms of AMI in an effort to prevent myocardial rupture.

Myocardial rupture accounts for approximately 5 to 20 percent of all deaths from acute myocardial infarction (AMI).I.11 Although rupture may involve the intraventricular septum and the papillary muscle, the free wall of the left ventricle is by far the most common." Various factors have previously been connected with myocardial rupture; however, no general agreement can be found in the literature on the risk factors and their relative importance. We report a well-defined, unselected patient population with myocardial rupture of the free wall of the left ventricle following AMI. These patients were compared with two matched control groups to characterize better the population at high risk for myocardial rupture.

diographic guidance in order to avoid myocardial penetration. In 31 cases, rupture of the left ventricular free wall was established at autopsy and in two patients the diagnosis was confirmed at surgery. The diagnosis of previous angina was made when there was a history of pain on exertion as stated by the patient. Previous myocardial infarction was defined as a previous admission to a hospital with this diagnosis. Hypertension was defined by a history of measurement and antihypertensive therapy, and hypotension when a blood pressure of 90 mm Hg or less was measured on at least three occasions. Mild heart f8ilure was defined by the presence of pulmonary rales or of dyspnea requiring treatment with a single dose of oral or IV diuretics or an increased dose ofdiuretics in patients already treated. Moderate heart failure was defined as failure requiring oral or IV diuretic treatment (or increased doses) or both twice a day at most. Severe heart f8ilure was defined as that requiring IV injection of diuretics three or more times daily. Control groups with AMI were matched fOr age and sex in each of the patients with ruptured myocardium: patients with non rupture cardiac death (group B)and patients discharged home (group C). The control subjects were selected as the next two admissions fulfilling the matching criteria after the patient with rupture. The groups were compared by Students t test (for mean values) and by Fisher's exact probability test (for discrete variables). Statistical significance was defined as p
MATERIALS AND METHODS

This study reviews the files of a series of consecutive patients with symptoms occurring within 24 hours and diagnosed as having AMI who were admitted to the ICCU of a regional hospital. All patients with suspected AMI are hospitalized in this ICCU without any preselection. The patients remain in the ICCU until they improve and are then discharged home or sent to departments of internal medicine for further care. It is the policy of the ICCU to mobilize the patients with AMI 24 hours after the event, unless complications occur. During the eight-year study period, a total of3,054 patients were admitted to the ICCU; of these, 1,737 (56.9 percent) had AMI as defined by WHO criteria. lJ Rupture of the left ventricle was diagnosed by a typical clinical picture in the presence of electromechanical dissociation. A perieardialtap was carried out by an experienced operator under electrocar*From the Department of Medicine "H," Tel-Aviv Medical Center, Ichilov Hospital, and Sackler School of Medicine, Tel-AvivUnive rsity, Tel-Aviv, Israel. Manuscript received November 24; revision accepted Jan~ 12. Reprint requut&: Prof Almog, lcldlov HoapItal, MedICine H , TelAviv, lamel 64239

RESUIXS

Patient Population During the study period, a total of 1,737 patients were diagnosed as having AMI (56.9 percent of all admissions); 1,279 were men. The age distribution was as follows: 41 percent were less than 59 years old, 32.9 percent between the ages of 60 and 69, and 26 percent of 70 years or more. The age and sex distributions are shown in detail in Table 1.

Mortality Of patients with AMI, 255 died during the study CHEST I 92 I 2 I AUGUST, 1987

218

Table I-Age and Sa DiBtribution in lbtientl with MyocardiGllnJdrction and Cardiac Death Sex and Age, yr

Total No. (%) of Patients With AMI

Total No. (%) of Patients with AMI Deaths

Group A

Group B

Group C

Men s59 60-69

1,279 (73.7) 593 (34) 409 (23.6) 277 (16) 458 (26.4) 113 (6.5) 166 (9.6) 179 (10.3) 1,737 (100) 713 (41) 571 (32.9) 453 (26)

156 (12.2) 33 (5.6) 59 (14.4) 64 (23.1) 99 (21.0) 10 (8.9) 33 (19.9) 56 (31.3) 255 (14.7) 43 (6) 92 (16.1) 120 (26.5)

23 6 12 5 17 0 10 7 40 6 22 12

23 6 10 7 17 2 7 8 40 8 17 15

23 5 11 7 17 2 8 7 40 7 19 14

~70

Women s59 60-69 ~70

All

s59 60-69 ~70

period (overall mortality, 14.7 percent). The causes of death were: low cardiac output (65.4 percent), myocardial rupture (15.7 percent), pulmonary emboli (6.7 percent), peripheral emboli (2.7 percent), primary arrhythmias and conduction disturbances (2 percent), noncardiac (1.2 percent), and unknown (6.3 percent). Women aged 60 to 69 years had the highest incidence of rupture, and 30.3 percent of the mortality in this age group was due to myocardial rupture (Table 2). The percentage of women with AMI and rupture of myocardium was significantly higher than that found in men. The median time from pain to death (Table 3) and from onset of pain to admission to the unit (Table 4) in the "rupture" group was not significantly different from the other groups. Forty percent of the ruptures occurred within 24 hours from the beginning of symptoms, and almost all of the ruptures occurred within one week after the beginning of pain. A relative delay in admission to the hospital was observed among the "rupture" patients when compared with the other groups (Table

4).

in control group B; however; anginal syndrome was most common among group A when compared with group C. No significant anamnestic difference was observed among the groups when the following factors were compared: hypertension, diabetes mellitus, and use of steroids, digoxin, and ~-blockers.

Hospitalization (Table 6) More patients with elevated blood pressure were found in group A. Low blood pressure was more frequently found in group B. Heart failure, especially severe, was most common among group B patients. No difference was found among the groups with regard to antiarrhythmic therapy with lidocaine. However, more patients in group C received quinidine-like antiarrhythmic drugs. The incidence of anterior mUI AMI was significantly higher among patients whose death was not due to rupture. Among group A patients, a higher incidence of prolonged chest pains was noted. Peak serum levels of cardiac enzymes were higher in group B patients.

Past History (Table 5)

DISCUSSION

More previous myocardial infarctions were observed Table 2-DiBtribution of Myocardial ~uptUf'8 by Age and Sa Sex and Age, yr

No.

% of AMI

% of Death

Men s59 60-69

23 6 12 5 17 0 10 7 40 6 22 12

1.8* 1 2.9 1.8 3.7* 0 6 3.9 2.3 0.8 3.9 2.6

14.7 18 20 7.8 17.2 0 30.3 12.5 15.7 14 23.9 10

~70

Women s59 60-69 ~70

All

s59 60-69 ~70

*Statistica1 comparison, p
220

The incidence of cardiac rupture in patients with AMI ranges from 1.5 to 8 percent in both general medical wards and ICCU. 7.11.13-16 Whereas, in the Table 3-Tame from Onset of Pai,.. to Death Statistical Comparison TIme, hr

Group A

Group B

Avs B

0-6

2 7 7 5 9 8 2

5 5 6 3 11 7 2 1

NS NS NS NS NS NS NS NS

6-12 12-24 24-48 48-96 96-168 168-336 >336

NS =not significant statistically. Cardiac RuptureIn Acute MyocardialInfarction (Shaplra st 8/)

Table 4-Time from Onaet of Poi... to Atlmiaion Statistical Comparison TIme, hr

Group A

Group B

Group C

Avs B

AvsC

Bvs C

0-8 4-6

10 10 9 7 3 1

16 9

17 10 9 3 1 1

NS NS NS NS NS NS

NS NS NS NS NS NS

NS NS NS NS NS NS

6-12 12-24 24-48 >48

8 4

1

2

NS =not significant statistically.

general medical ward cardiac rupture is responsible for 5 to 12 percent of AMI fabilities,1.8 the proportion of deaths in the ICCU from this cause is higher (7.9 to 23.5 percent),15.16 apparently because of lower overall mortality and unchanged number of cases with myocardial rupture," which is almost invariably fatal. These data are in accordance with the present series; 2.3 percent of patients with AMI had cardiac rupture, while 15.8 percent of the overall mortality was due to myocardial rupture. The most common type of rupture is by far the acute rupture of the free wall. Successful surgical intervention has been reported rarely.":" In the present series dealing only with patients with free wall rupture, surgical attempts in two patients were unsuccessful. The patients reported in various series appear to have less associated diseases, when compared with patients dying from other causes.1.10,ll.IO,21 In the present series previous angina was observed in 44 percent of the cases with myocardial rupture and this was significantly lower than in survivors of AMI. Some previous studies on myocardial rupture emphasize the fact that women had a higher incidence of rupturev'':" while others claim the opposite. 10 According to the present study, the percentage of rupture is higher in women. The age distribution is also of interest: 30.3 percent of the deaths among women aged 60 to 69 was due to myocardial rupture. Regarding the time lapse from the onset of symptoms ofAMI to admission to the unit or to death we did

not find any significant difference among the three groups. In 40 percent of our patients,3,4,7,14 rupture occurred within the first 24 hours after onset of pain. These findings can be explained by the fact that some of these cases are silent AMI and that the onset of chest pain leading to the diagnosis has actually been caused by the dissection through the already infarcted heart muscle. II Indeed, on pathologic examination, the age of the infarction was repeatedly found to be older than expected on clinical grounds. Recently, Bashour et al23 reported an interesting case of myocardial rupture before any pathognomonic clinical or pathologic sign of infarction developed. Severe, prolonged chest pain was much more prominent in patients who had cardiac rupture than in the control groups. This clinical feature was very useful in alerting the clinician to the possible imminent rupture of the myocardium. Several works support these findings. 4,ll.20 During hospitalization, hypertension1. 7,9,10,10 and unusual effort,4,18,24 have been found to be associated with increased incidence of rupture. Hypertension was found in our series to be more prevalent in group A. However, several considerations indicate that systolic hypertension may not be a major factor leading to myocardial rupture, which may even occur in patients without high blood pressure. In our series, although statistically more common than in other groups, only one third of patients developing rupture suffered from systolic hypertension. Dellborg et al'' even suggest that if rupture does not OCCUI; sustained hypertension may be regarded as a sign of better preserved ventricular function, and thus as a good prognostic sign. This may be correct, when expressed retrospectively. However, in our opinion, systolic hypertension should be looked for carefully and treated promptly.. The data regarding the association of increased physical stress and myocardial rupture are difficult to interpret; all patients in this series were mobilized gently after 24 hours, without differing from other groups.

Table 5-PreviouB Medical Hiatary of Pattent8 in aU Group. Statistical Comparison (P) Medical history

Group A

Previous AMI Anginal syndrome Hypertension Diabetes mellitus (insulin treatment) Diabetes mellitus (noninsulin treatment) Steroid treatment Digoxin treatment p-Blockers (treatment)

11 17

20

17 21 14

4

Group C

Avs B

7 29

4

20 1

NS NS NS NS

10

12

16

1 2 2

1 7

0 3 2

-Group B

4

AvsC

BvsC

NS

<0.05

0.05 NS NS

NS NS NS

NS

NS

NS

NS NS NS

NS NS NS

NS NS NS

CHEST I 92 I 2 I AUGUST, 1987

221

Table 6-ClinictJl Coune and Treatment of PtJtienta in all Group' Statistical Comparison, p Group A Hypertension Hypotension Penistent pains Drug treatment Udocaine Quinidine-like Heart failure Mild Moderate Severe

Total

MI location Anterior Inferior + posterior Subendocardial Undetermined Cardiac enzymes CPKt ASn

Ldhl

Group 8

Group C

Avs 8

AvsC

8vsC

13 8 20

3 35 10

5 2 8

<0.01 <0.001 <0.05

<0.05 NS <0.05

NS <0.0001 NS

12 4

13 4

11 19

NS NS

NS <0.005

NS <0.005

11 6 2 19

15 17 37

5

13 4 7 24

<0.05 <0.05 <0.05 <0.0001

NS NS NS NS

<0.05 <0.05 <0.05 <0.001

81 1

25 13 1 1

<0.005 <0.005 NS NS

<0.05 <0.05 NS NS

NS NS NS NS

632.4±413.9 144.7± 113.2 1412±843.4

481.1 ± 255.1 87.6±66.6 858.7 ± 478.7

<0.0001 <0.0001 <0.0001

NS <0.05 NS

<0.0001 <0.0001 <0.0001

16 22 0 2 483.3 ± 335.7 92.4±72.6 866.6±675.0

30·

·Statistical comparison, p
*Normal value, 7-40 mU/ml. INormal value, 160-320 mU/ml.

O'Rourke" introduced the term, subacute heart rupture. These patients have generally been hypotensive, with severe right heart failure. Indeed, in our series, 20 percent of the patients with myocardial rupture had hypotension and moderate to severe heart failure. These findings are similar to those reported by Dellborg et al," who found 30 percent of all ruptures to be subacute. There is controversy regarding the locationof infarction leading to rupture.I.4.u.I1·18-17 In the present series, inferior wall myocardial infarction was more frequent. The extension of the infarction as determined by serum enzyme activity had no influence on the incidence of rupture, although Dellborg et al" found a correlation between this complication and large infarcts. Resuscitation measures, such as external massage and intracardiac injections, have been suggested as possible causes of cardiac ruptures." However, although these procedures have been performed in most of the patients, there was no evidence at autopsy that these maneuvers were related to rupture. This study has several limitations. First, it was carried out retrospectively, and thus we were unable to obtain all the desirable clinical characteristics. Further, the study is over an eight-year period, covering the "pre-modern" era of cardiology and data from current imaging methods were largely unavailable. However, the number of patients reported is relatively large and the findings "nail down" the epidemiology of 222

cardiac rupture. The present consecutive series of patients with AMI, representing an essentially unselected population admitted to the same department and handled according to uniform criteria, indicates that patients with the highest risk for myocardial rupture are women, aged 60-69 years, with sustained chest pain and hypertension. The rupture occurs within the first to seventh day after the onset of the symptoms. In only a few cases can patients who have already developed rupture be salvaged by emergency operation. Therefore, it is of crucial importance to define the patients at risk for this complication. Possible implications of this study include a role for a more aggressive prophylactic approach, including early reperfusion or revascularization and a better control of the hypertension in this group of patients. Improved understanding of this dreaded complication is required for effective prevention. REFERENCES 1 Naeim F, de la Maza L, Robbius SL. Cardiac rupture during myocardial infarction. Circulation 1972; 45:1231-39 2 Lewis AJ, 8urchell H8, TItus JL. Clinical and pathologic features ofpost-infarction cardiac rupture. Am J Cardioll969; 23:43-53 3 GriBith GC, Hedge 8, Oblath RW Factors in myocardial rupture. Am J Cardioll961; 8:792-98 4 London RE, London S8. Rupture of the heart. Circulation 1965; 31:202-08 5 Levene A. Spontaneous rupture of the heart. 8r Heart J 1960;

22:660-70

6 Edmondson HA, Hoxie HJ. Hypertension and cardiac rupture. C8rdiac RuptureIn Acute Myocardial Infarction (Shapira et Ii)

Am Heart J 1942; 24:719-33 " ". 7 Sievers J. Cardiac rupture in acute myocardial infarction. "Geriatrics 1966; 21:125-30 8 Maher JF, Mallory GK, Laurenz GA. Rupture oft-be-beaJ1.r myocardial infarction. N Eng} J Med 1956; 255:1-10 ." 9 Christensen DJ, Ford M, Reading J, Castle CH. Effect of hypertension on myocardial rupture after acute myocardial infarction. Chest 1977; 72:618-22 10 Feneley M~ Chang ~ O·Rourke MF: Myocardial rupture after acute myocardial infarction: ten year review Br Heart J 1983; 49:550-56 11 Dellborg M, Held ~ Swedberg Ie, Vedin A. Rupture of the myocardium: occurrence and risk factors. Br Heart J 1985; 54:11-16 12 WHO, Regional OfIice for Europe. Report ofworking group on ischemic heart disease registers. Copenhagen: Annex 1972; 1:27 13 Cjol M. Cardiac rupture and acute myocardial infarction. Geriatrics 1972; 27:126-29 14 Rasmussen S, Leth A, Iejoller E, Pederson A. Cardiac rupture in acute myocardial infarction: a review of 72 consecutive cases. Acta Med Scand 1979; 205:11-16 15 Helmers C. Short and long term prognostic indices in acute myocardial infarction. Acta Med Scand [Suppl] 1974; 555:1-22 16 Hofvental S. Influence of treatment in a coronary care unit on prognosis in acute myocardial infarction. Acta Med Scand [Suppl] 1971; 519:1-78 17 Bashour Kabbani SS, Ellertson DC, et ale Surgical salvage of

n

18

19

20 21 22 23 24 25 26 27

heart rupture: report of two cases and review of the literature. Ann Tborac Surg 1983; 36:209-18 Kendall ~ DeWood MA. Postinfarction cardiacrupture: surgical suecess.and review of the literature. Ann Thorac Surg 1974; 25:311-15 Yakirevitch ~ Shapira I, Miller HI, et ale Successful surgical treatment of a ruptured right ventricle. Isr J Med Sci 1982; 18:864-96 Bates RJ, Beutler S, Resnekov L, Anagnostopolous CEo Cardiac rupture-challenge in diagnosis and management. Am J Cardiel 1977; 40:429-37 Wessler S, Doll PM, Schlesinger MJ. The pathogenesis of spontaneous cardiac rupture. Circulation 1952; 6:334-51 Lantsch E~ Lanks KW Pathogenesis of cardiac rupture. Arch Patholl967; 84:264-71 Bashour Antonini C, 1llylor D. Cardiac rupture before Completed myocardial in&retion. Am Heart J 1986; 112:176-78 Muers A AR, Vos AK, Verhey JB, Gerbrandy J. Electrocardiogram during cardiac rupture by myocardial infarction. Dr Heart J 1970; 32:232-36 O·Rourke ME Subacute heart rupture fOllowing myocardial infarction. Lancet 1973; 2:124-26 Havig O. Cardiac rupture in recent myocardial infarction. Acta Pathol Microbial Scand [A] 1973; 8:501-06 Hashell WK. Physical activity after myocardial infarction. Am J Cardio11974; 33:776-81

n

CHEST I 92 I 2 I AUGUST. 1887

223