The Causes, Treatment, and Outcome of Acute Heart Failure in 1006 Africans From 9 Countries:  Results of the Sub-Saharan Africa Survey of Heart Failure

We have read with interest the article by Damasceno et al., which reports experience with the THESUS-HF study carried out in sub-Saharan Africa on the causes, treatment and outcome of 1006 patients with acute heart failure (AHF) (1). This article reminds us of the necessity of considering cardiovascular disease as a priority in developing countries where young patients’ ability to work is seriously compromised by AHF (2). The authors refer to the European Guidelines of 2005 for chronic heart failure to outline the probable causes of AHF. It would have been better to reference the Guidelines for AHF (3). 

We would like to bring several aspects of the study to the attention of the authors. 

1) Whether or not the patients in the study were consecutive should be reported as this could lead to an important selection bias.

2) Excluding patients with myocardial infarction likely reduced the number of patients suffering from acute ischemic heart failure.

3) Not having an ECG on about 19% of patients and not testing about half of those patients for HIV may have affected the results. 

4) The observed high value of the mean left ventricular ejection fraction, near normal cutoff points in some previous studies on heart failure, might be explained by diastolic dysfunction and/or the type of center where patients were examined (university hospitals) (4).

5) That the in-hospital death rate due to endemic disease was double that due to emerging causes may be attributable to the differing evolution of the infective or post-infective forms compared to the chronic-degenerative forms of the disease.

6) Obesity in women patients was about twice that in men, and it would be interesting to extend the study to look at diet, as was done in a small group of patients studied in Soweto (5).

7) That 43% of the patients studied were Nigerian is an important consideration with regard to the results such as in Figure 3 where about 60% of Nigerian AHF patients were hypertensive and about 70% of the Ethiopians had dilative cardiomyopathy.

8) It would be interesting to have a general comment regarding the various efficacies of pharmaceutical treatment in black patients compared to whites, and specifically on the limited use in this study of the combination treatment of isosorbide dinitrate and hydralazine, which have been shown to be efficacious in black American subjects (6, 7).

9) The causes of AHF observed in this study probably do not reflect data from rural areas, as indicated in the study by Tantchou Tchoumi et al. (8). 

10) The difficulty in following-up patients, for cultural and socioeconomic reasons, may have led to lower patient adherence to the therapy.

11) We recommend use of telemedicine in regard to the above points 6, 7 and 9, to facilitate the exchange of information between “hub” medical centers and “spokes” or peripheral centers.

12) The data on smoking in Table 1 are very interesting. The relationship between smoking and hypertension, although not explicitly calculated according to these published data, is low, which corresponds to our own observational studies. We also saw that smoking was not significantly related to hypertension (9). 

In conclusion, Damasceno et al.’s study is particularly interesting due to the geographical zone considered and their observed results. We recommend some caution in generalizing some of these results owing to the previous points raised. 

References

1) Damasceno A, Mayosi BM, Sani M et al. The causes, treatment, and outcome of acute heart failure in 1006 Africans from 9 countries. Arch Intern Med. 2012 Sep 3:1-9. doi: 10.1001/archinternmed.2012.3310.

2) Fuster V, Voute J, Hunn M, Smith SC, Jr. Low priority of cardiovascular and chronic diseases on the global health agenda: A cause for concern. Circulation 2007;116:1966-1970.

3) Nieminen MS, Böhm M, Cowie MR et al. Executive summary of the guidelines on the diagnosis and treatment of acute heart failure. The Task Force on Acute Heart Failure of the European Society of Cardiology. Eur Heart J 2005;26:384-416.

4) Lenzen MJ, Scholte OP, Reimer WJM, Boersma E, et al. Differences between patients with a preserved and depressed left ventricular function: a report from EuroHeart Failure Survey. Eur Heart J 2004;25:1214-1220.

5) Pretorius S, Sliwa K, Ruf V, Walker K, Stewart S. Feeding the emergence of advanced heart disease in Soweto: a nutritional survey of black African patients with heart failure. Cardiovasc J Afr 2012;23:245-251.

6) Jamerson KA, Agodoa L. Hypertension as an emerging risk factor for acute heart failure in Africa. Arch Intern Med. 2012 Sep 3:1-2. doi: 10.1001/archinternmed.2012.4491.

7) Shroff GR, Taylor AL, Colvin-Adams M. Race-related differences in heart failure therapies: simply black and white or shades of grey? Curr Cardiol Rep. 2007;9:178-181.

8) Tantchou Tchoumi JC, Ambassa JC, Kingue S et al. Occurence, aetiology, and challenges in the management of congestive heart failure in sub-Sarahan Africa: experience of the Cardiac Centre in Shisong, Cameroon. Pan Afr Med J. 2011;8:11.

9) Sossai P, Amenta F, Porcellati C. Observational study of hypertension in Matelica, Italy (Matelica Hypertension Study). Clin Exp Hypertens. 2007; 29:531-537.