Annotations

Spontaneous changes in the severity of angina

pectoris”

Angina is known to be affected by many extra-cardiac factors, such as changes in the weather, changes in body weight, the development of anaemia, cervical spondylosis, duodenal ulcer- ation, and disease of the biliary tract. But sometimes angina becomes steadily worse in the absence of any recognizable extra-cardiac factor and sometimes it gradually subsides and disappears. How common are these spontaneous changes in the severity of angina and what is their outcome?

Three hundred and seventeen patients with angina asso- ciated with ischemic heart disease were followed until death or until an average of six and a half years had elapsed from the onset of their symptoms. (Cases in which the angina was due to valvular heart disease or non-coronary cardiomyopathy were excluded.) The male/female ratio was 1.3:1 and the median age for the onset of angina was in the sixth decade for men and in the seventh decade for women.

Crescendo angina. In 84 patients (a little over a quarter of the total) the angina became progressively more easily induced in the absence of any detectable extra-cardiac factor and without change in treatment. In half these patients (41) the crescendo phase culminated in myocardial infarction or sudden death; in the remainder it gradually subsided to its previous level of intensity. In a few instances the crescendo phase was associated with evidence of heart failure or deteri- oration in the electrocardiogram suggesting a small myocar- dial infarct or coronary thrombosis; but in the majority there was no objective clinical evidence of deterioration in the cardiovascular system.

The crescendo phase was found to develop at any time from the first week to as long as 33 years after the onset of the angina. The interval between the onset of the crescendo phase and the development of incapacity ranged from two days to almost a year; in half the incapacity developed within a month, and in three-quarters within three months.

It is difficult to compare our findings with those of previous workers, because cases of crescendo effort angina have usually been included with cases of recent onset effort angina and cases of spontaneous angina at rest in a group now commonly referred to as “unstable angina.” The valuable reports of Levy’ and Duncan and associates’ illustrate this problem. Levy’ reviewed the course of 158 patients with what he called “changing patterns of angina” and found that nearly 40 per cent proceeded to myocardial infarction or sudden death. Duncan and colleagues* studied the natural history of 251 patients with what they termed “new or worsening angina,” and found that only 16 per cent developed myocardial infarc-

‘We are indebted to the British Heart Foundation for a generous grant in support of this study.

060%8703/78/0396-0415$00.10/O 0 1978 The C. V. Mosby Co.

tion or died suddenly. An important difference between the two series lies in the relative proportion of cases of recent onset angina and crescendo angina. Cases of crescendo angina formed 67 per cent of Levy’s series whereas they accounted for only 41 per cent of the Edinburgh series. Both reports are consistent with our finding that approximately half the patients developing spontaneous crescendo angina proceed to myocardial infarction or sudden death.

Spontaneous subsidence of angina. In 55 patients (one- sixth of the total) angina ceased spontaneously for at least some months (without the development of myocardial infarc- tion); and in half (28) of these it had not returned by the end of the period of observation. In two-thirds of the cases, the subsidence occurred within a year of the onset, but three patients lost their angina after it had been present for three years, and one after ten years. Those whose angina subsided did not differ from other patients with angina in respect of sex or associated hypertensive heart disease. Rather more than average had a normal previous electrocardiogram, yet almost half had evidence of previous myocardial infarction or a major electrocardiographic abnormality.

In the Framingham Study” angina was noted as ceasing spontaneously in 30 per cent of subjects. This is almost double the proportion in our series, but the Framingham Study probably included patients with angina which was too mild to necessitate referral for cardiological advice. In any case, it is clear that a considerable proportion of patients with angina do lose their symptoms, even after the angina has been present for several years. It is possible that this natural tendency is counteracted by recalling patients for frequent follow-up examination, with the consequent focusing of their attention on their hearts.

David Short, Ph.D., F.R.C.P. Consultant Physician

Mary Stowers, M.B., B.S. Research Assistant

Aberdeen Royal Infirmary Foresterhill

Aberdeen, A B9 2ZB Scotland

REFERENCES

1. Levy, H.: Natural history of changing patterns of angina pectoris, Ann. Intern. Med. 44:1123, 1956.

2. Duncan, B., Fulton, M., Morrison, S. L., et al: Prognosis of new and worsening angina pectoris, Rr. Med. J. 1:981, 1976.

3. Kannel, W. B., and Feinleib, M.: Natural history of angina pectoris in the Framingham study. Prognosis and survival, Am. J. Cardiol. 29:154, 1972.

American Heart Journal 415