Improved Diagnosis through Diastolic Hyperemia-Free Ratio (DFR) over Fractional Flow Reserve (FFR) in Intermediate Coronary Lesions

OBJECTIVES

To compare the fractional flow reserve (FFR) and diastolic hyperemia-free ratio (DFR) measurements in a population with intermediate coronary artery stenosis and improve the diagnosis.

BACKGROUND

Visual assessment of coronary artery stenosis severity, particularly in intermediate lesions, is prone to errors in decision-making. FFR provides a reliable assessment of functional severity in these cases but requires hyperemia induction by adenosine, which has side effects and increased cost. DFR is a novel hyperemia-independent index, which could be used as an alternative to adenosine-based hyperemia induction.

METHODS AND RESULTS

Between September 2019 to March 2020, 25 patients with 38 intermediate coronary stenotic lesions were included in the study. All patients underwent assessment of whole cycle Pd/Pa (ratio of distal coronary pressure to proximal aortic pressure), DFR and FFR. Mean whole cycle Pd/Pa, DFR and FFR were 0.93±0.06, 0.88±0.09, and 0.85±0.08, respectively. A significant positive correlation between DFR and FFR [r = 0.74; p<0.001] was observed. Receiver operating characteristic analysis showed an area under the curve of 0.90. DFR-only strategy with a treatment cut-off of ≤0.89 showed a diagnostic agreement with the FFR-only strategy in 74% of lesions, with a sensitivity of 54%, specificity of 82%, a positive predictive value of 60%, and a negative predictive value of 79%.

CONCLUSIONS

Real-time DFR measurements show a clinically reliable correlation with FFR. Hence, using DFR is likely to avoid adenosine administration as well as reduce the cost and procedural time. Further studies with a larger sample size would be ideal to evaluate specific cut-off values and endpoints.

Demographic analysis and clinical outcomes of COVID-19 and myocardial infarction from a tertiary care centre in south India

Funding Acknowledgements

Type of funding sources: None.

Back ground – COVID-19  is reported in India from March 2020. It is known to cause  myocarditis , arrythmias and heart failure. COVID-19 infection has been proposed to be associated with myocardial infarction.

PURPOSE

–We intent to study outcomes of acute coronary syndrome associated with  COVID-19 patients .

METHODS

– This is a  single center case-control study done in an University hospital in south India ,  from May 2020 to October 2020 . Data of patients who came with acute coronary syndrome (ACS) with COVID- 19 were collected retrospectively from the hospital database. The clinical outcomes of the these patients were compared with the patients who were admitted in the hospital for ACS without  COVID -19  in the same period.

RESULITS – 508  patients were admitted between May 2020 to October 2020  with ACS and out of which  58 patients were positive for COVID-19 and 450 patients were COVID-19 negative.  In COVID positive group, most of the patients were above 50 years  with 17 % of them being female sex.  60 %  were having diabetes and 44.8 % had hypertension . 55%  of them had STEMI with the rest being  NSTE- ACS . 43.1 %  patients were thrombolysed . 25% patients underwent revascularization either with  PCI / CABG . 10.3% died in the COVID - 19 positive group ,  at the same time there were only  2.2 % deaths in the control group . Most the patients were asymptomatic COVID-19 at presentation . Among the symptomatic COVID-19  patients the onset of myocardial infarction after COVID-19 ranged from 9 – 90 days .

CONCLUSION

– Acute coronary syndrome in COVID-19 patients  can present as late  as 3 months after index infection,  and these patients had higher mortality compared with those who did not have COVID -19 .