Cardiovascular Journal of Africa: Vol 32 No 3 (MAY/JUNE 2021)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 3, May/June 2021

AFRICA

127

patients had a normal-weight BMI value. Therefore, our results

are different from those of Ades

et al

. in that the endothelial

function could be improved after exercise training, irrespective

of the initial BMI value. A similar effect occurred in both of our

patient groups.

The high-density lipoprotein (HDL) cholesterol level might

have decreased in both groups because we used high-intensity

statin treatment to reduce LDL cholesterol levels. The change

in the HDL cholesterol level was statistically significant, but

decreased only by a small amount (2 mg/dl; 0.05 mmol/l). We

do not suggest that this change was clinically significant and we

should have applied more effort to reduce the LDL cholesterol

level of the ACS group so that the target goal could be achieved.

The VO

2max

, MMET, exercise duration and FMD results

were improved at six months in each group, but there were

no statistically significant between-group differences in these

parameters. One reason for these results might be that the

patients with severe heart failure [left ventricular ejection fraction

(LVEF) 30%] were excluded from the ACS group.

Limitations

Our study had several limitations. First of all, we did not

perform the comparison analysis between the patients who

performed CR versus those who did not. Furthermore, this

study was a retrospective study and we analysed registry data

that included only patients who had received CR after PCI;

therefore, the FMD data of patients who did not receive CR

or PCI were unavailable. In addition, there was a significant

difference in the patients’ age and the use of ARBs or ACEIs;

these differences were considered to affect atherosclerosis and

endothelial function between the two groups. Despite these

differences, the FMD values were improved in both groups when

compared to the baseline, and this improvement was similar

between the two groups. On the other hand, many previous

studies have shown that cardiac rehabilitation has a benefit in

improving endothelial function in patients with coronary events,

and our study was performed based on these previous results.

Second, we measured FMD while the patients received

standard medical treatment for ischaemic heart disease, including

ARBs or ACEIs, beta-blockers and statins; these treatments

could have affected the FMD results. However, we performed

the examination under the same conditions for both groups,

at baseline and six months after CR was initiated. Therefore,

we suggest that the improvement in FMD after the six-month

CR programme was independent of the drugs taken by the

patients. Compared to other study populations, patients who

had relatively less-serious disease could be enrolled in this

study. Therefore, patients with unstable angina might have been

included in the stable-angina patient group.

Third, except for seven ST-elevation myocardial infarction

(STEMI) patients, PCI was performed via the subject’s right

arm, followed by measuring the FMD on the right arm within

two weeks. In a recent study, Heiss

et al

. suggested that trans-

radial catheterisation leads to dysfunction, not only of the radial

artery, but also upstream of the brachial artery; they suggest

that FMD should be interpreted with caution after trans-radial

catheterisation.

Therefore, if we had measured FMD using the

patients’ left arm, we would have been able to see a little more

clearly that the FMD improved.

Our study results did not suggest that there were improvements

in LVEF as the FMD increased, especially in the ACS group. We

also found no beneficial effect with regard to clinical outcome

by improving the FMD result. The study duration was six

months, which was a relatively short period of time. Patients

with less-severe disease and a small number of patients were

enrolled in the study. No major adverse cardiac event occurred

during the six-month CR period. A long-term follow-up period

of one year or more would be required to determine whether

the improvements in FMD would affect the LVEF and clinical

outcomes.

Conclusion

This study revealed that the FMD was equally improved after a

successful PCI and a six-month CR programme for both ACS

and stable-angina patients. The ACS patients tended to have a

lower FMD before CR, compared to the patients with stable

angina. Therefore, it is suggested that the endothelial function

might be improved after planned CR in patients who received

PCI, irrespective of whether they had ACS or stable angina.

References

Ades PA, Savage PD, Lischke S, Toth MJ, Harvey-Berino J, Bunn JY,

et al

. The effect of weight loss and exercise training on flow-mediated

dilatation in coronary heart disease: a randomized trial.

Chest

2011;

140

: 1420–1427.

Kwan G, Balady GJ. Cardiac rehabilitation 2012: advancing the field

through emerging science.

Circulation

2012;

125

: e369–373.

Lee HY, Kim JH, Kim BO, Byun YS, Cho S, Goh CW,

et al.

Regular

exercise training reduces coronary restenosis after percutaneous coro-

nary intervention in patients with acute myocardial infarction.

Int J

Cardiol

2013;

167

: 2617–2622.

Morikawa Y, Mizuno Y, Harada E, Katoh D, Kashiwagi Y, Morita S,

. Aerobic interval exercise training in the afternoon reduces attacks of

coronary spastic angina in conjunction with improvement in endothelial

function, oxidative stress, and inflammation.

Coron Artery Dis

2013;

: 177–182.

Myers J, Prakash M, Froelicher V, Do D, Partington S, Atwood JE.

Exercise capacity and mortality among men referred for exercise testing.

N Engl J Med

2002;

346

: 793–801.

Fichtlscherer S, Breuer S, Zeiher AM. Prognostic value of systemic

endothelial dysfunction in patients with acute coronary syndromes:

further evidence for the existence of the “vulnerable” patient.

Circulation

2004;

110

: 1926–1932.

Nigam A, Mitchell GF, Lambert J, Tardif JC. Relation between

conduit vessel stiffness (assessed by tonometry) and endothelial func-

tion (assessed by flow-mediated dilatation) in patients with and without

coronary heart disease.

Am J Cardiol

2003;

: 395–399.

Schachinger V, Britten MB, Zeiher AM. Prognostic impact of coronary

vasodilator dysfunction on adverse long-term outcome of coronary

heart disease.

Circulation

2000;

101

: 1899–1906.

Moens AL, Goovaerts I, Claeys MJ, Vrints CJ. Flow-mediated vasodila-

tion: a diagnostic instrument, or an experimental tool?

Chest

2005;

127

2254–2263.

10. Shechter M, Issachar A, Marai I, Koren-Morag N, Freinark D, Shahar

et al

. Long-term association of brachial artery flow-mediated vasodi-

lation and cardiovascular events in middle-aged subjects with no appar-

ent heart disease.

Int J Cardiol

2009;

134

: 52–58.