Prognostic value of age, creatinine, and left ventricular ejection fraction risk score in patients evaluated with fractional flow reserve: a cross-sectional study

OBJECTIVE

In this study, we investigated the relationship between age, creatinine, and left ventricular ejection fraction risk score and the severity of coronary lesions detected by applying fractional flow reserve in the patient group presenting with chronic coronary syndrome. Also, we presented long-term follow-up results in patients whose age, creatinine, and left ventricular ejection fraction score was evaluated by the fractional flow reserve procedure.

METHODS

This study was planned retrospectively and in two centers. For this purpose, 114 patients who met the study criteria and who underwent elective fractional flow reserve between January 2014 and January 2019 were included in the study. Age, creatinine, and left ventricular ejection fraction was calculated as age/left ventricular ejection fraction +1 (if estimated glomerular filtration rate<30 mL/min).

RESULTS

They were divided into two groups according to the cutoff value of the age, creatinine, and left ventricular ejection fraction score. A total of 76 patients had an age, creatinine, and left ventricular ejection fraction score of ≤1.17 (Group I) and 38 patients had an age, creatinine, and left ventricular ejection fraction score of >1.17 (Group II). The number of patients with severe lesions in fractional flow reserve was significantly higher in Group II compared with Group I (60.5 vs. 32.9%, p=0.005). According to the Kaplan-Meier analysis, a significant increase was observed in major adverse cardiac events and mortality during the follow-up period in the group with a high-risk score (Log Rank: 15.01, p<0.001 and Log Rank: 8.51, p=0.004, respectively).

CONCLUSION

In light of the data we obtained from our study, we found a correlation between the severity of the lesion detected in fractional flow reserve and the age, creatinine, and left ventricular ejection fraction scores. In addition, we found that patients with high age, creatinine, and left ventricular ejection fraction scores had higher mortality and major adverse cardiac events rates during follow-up.

Discordance Between Fractional Flow Reserve and Coronary Flow Reserve: Insights From Intracoronary Imaging and Physiological Assessment

OBJECTIVES

The aim of this study was to investigate the epicardial and microvascular substrates associated with discordances between fractional flow reserve (FFR) and coronary flow reserve (CFR) values.

BACKGROUND

Discordances between FFR and CFR remain poorly characterized.

METHODS

FFR, hyperemic stenosis resistance (HSR), and intravascular ultrasound were performed as indexes of epicardial function and CFR and hyperemic microvascular resistance (HMR) as measures of microvascular function in 94 patients with moderate coronary stenosis. Maximal plaque burden (PB_max), HSR, and HMR were calculated in 4 quadrants based on values of FFR ≤0.80 and CFR ≤2.0 as follows: concordant normal (preserved FFR and CFR), concordant abnormal (low FFR and CFR), discordant low FFR and preserved CFR, and discordant preserved FFR and low CFR.

RESULTS

Sixty-four patients (68%) had concordant FFR and CFR findings, and 30 patients (32%) had discordant FFR and CFR. Compared with patients with preserved FFR and CFR, those with low FFR and CFR had higher PB_max (p = 0.003), higher HSR (p < 0.001), and similar HMR. Among patients with preserved FFR, those with reduced CFR had similar PB_max and HSR but a trend toward higher HMR (p = 0.058) compared with patients with preserved CFR. Among patients with reduced FFR, those with preserved CFR had lower PB_max (p = 0.004), a trend toward lower HSR (p = 0.065), and lower HMR (p = 0.03) compared with patients with reduced CFR. Furthermore, compared with patients with preserved FFR and low CFR, those with low FFR and preserved CFR had higher HSR (p = 0.022) but lower HMR (p = 0.003).

CONCLUSIONS

In patients with moderate coronary stenosis, preserved FFR and low CFR is associated with increased microvascular resistance, while low FFR and preserved CFR has modest epicardial stenosis and preserved microvascular function.

Integrated Noninvasive Physiological Assessment of Coronary Circulatory Function and Impact on Cardiovascular Mortality in Patients With Stable Coronary Artery Disease

BACKGROUND

It is suggested that the integration of maximal myocardial blood flow (MBF) and coronary flow reserve (CFR), termed coronary flow capacity, allows for comprehensive evaluation of patients with known or suspected stable coronary artery disease. Because management decisions are predicated on clinical risk, we sought to determine the independent and integrated value of maximal MBF and CFR for predicting cardiovascular death.

METHODS

MBF and CFR were quantified in 4029 consecutive patients (median age 66 years, 50.5% women) referred for rest/stress myocardial perfusion positron emission tomography scans from January 2006 to December 2013. The primary outcome was cardiovascular mortality. Maximal MBF <1.8 mL·g^-1·min^-1 and CFR<2 were considered impaired. Four patient groups were identified based on the concordant or discordant impairment of maximal MBF or CFR. Association of maximal MBF and CFR with cardiovascular death was assessed using Cox and Poisson regression analyses.

RESULTS

A total of 392 (9.7%) cardiovascular deaths occurred over a median follow-up of 5.6 years. CFR was a stronger predictor of cardiovascular mortality than maximal MBF beyond traditional cardiovascular risk factors, left ventricular ejection fraction, myocardial scar and ischemia, rate-pressure product, type of radiotracer or stress agent used, and revascularization after scan (adjusted hazard ratio, 1.79; 95% confidence interval [CI], 1.38-2.31; P<0.001 per unit decrease in CFR after adjustment for maximal MBF and clinical covariates; and adjusted hazard ratio, 1.03; 95% CI, 0.84-1.27; P=0.8 per unit decrease in maximal MBF after adjustment for CFR and clinical covariates). In univariable analyses, patients with concordant impairment of CFR and maximal MBF had high cardiovascular mortality of 3.3% (95% CI, 2.9-3.7) per year. Patients with impaired CFR but preserved maximal MBF had an intermediate cardiovascular mortality of 1.7% (95% CI, 1.3-2.1) per year. These patients were predominantly women (70%). Patients with preserved CFR but impaired maximal MBF had low cardiovascular mortality of 0.9% (95% CI, 0.6-1.6) per year. Patients with concordantly preserved CFR and maximal MBF had the lowest cardiovascular mortality of 0.4% (95 CI, 0.3-0.6) per year. In multivariable analysis, the cardiovascular mortality risk gradient across the 4 concordant or discordant categories was independently driven by impaired CFR irrespective of impairment in maximal MBF.

CONCLUSIONS

CFR is a stronger predictor of cardiovascular mortality than maximal MBF. Concordant and discordant categories based on integrating CFR and maximal MBF identify unique prognostic phenotypes of patients with known or suspected coronary artery disease.

Long-Term Clinical Outcomes of Fractional Flow Reserve-Guided Versus Routine Drug-Eluting Stent Implantation in Patients With Intermediate Coronary Stenosis: Five-Year Clinical Outcomes of DEFER-DES Trial

BACKGROUND

We aimed to compare the long-term clinical outcomes between fractional flow reserve (FFR)-guided and routine drug-eluting stent (DES) implantation in patients with an intermediate coronary stenosis.

METHODS AND RESULTS

A total of 229 patients with an angiographically intermediate coronary stenosis were randomly assigned to FFR-guided or Routine-DES implantation group. For FFR-guided group (n=114), treatment strategy was determined according to the target vessel FFR (FFR<0.75: DES implantation [FFR-DES group]; FFR≥0.75: deferral of stenting [FFR-Defer group]). Routine-DES group underwent DES implantation without FFR measurement (n=115). The primary end point was the incidence of major adverse cardiac events, a composite of cardiac death, myocardial infarction, and target lesion revascularization. Of lesions assigned to FFR-guided strategy, only one quarter had functional significance (FFR<0.75). At 2-year follow-up, the cumulative incidence of major adverse cardiac events was 7.9±2.5% in the FFR-guided group and 8.8±2.7% in Routine-DES group (P=0.80). At 5-year follow-up, the cumulative incidence of major adverse cardiac events was 11.6±3.0% and 14.2±3.3% for the FFR-guided group and the Routine-DES group (P=0.55). There was no difference in major adverse cardiac events rates between the 2 groups ≤5-year follow-up (hazard ratio, 1.25; 95% confidence interval, 0.60-2.60).

CONCLUSIONS

In lesions with angiographically intermediate stenosis, FFR guidance provides a tailored approach, which is at least as good as an angiography-guided routine-DES implantation strategy and avoids unnecessary DES-stenting in a considerable part of the patients.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00592228.

Quality-of-Life and Economic Outcomes of Assessing Fractional Flow Reserve With Computed Tomography Angiography: PLATFORM

BACKGROUND

Fractional flow reserve estimated using computed tomography (FFRCT) might improve evaluation of patients with chest pain.

OBJECTIVES

The authors sought to determine the effect on cost and quality of life (QOL) of using FFRCT instead of usual care to evaluate stable patients with symptoms suspicious for coronary disease.

METHODS

Symptomatic patients without known coronary disease were enrolled into 2 strata based on whether invasive or noninvasive diagnostic testing was planned. In each stratum, consecutive observational cohorts were evaluated with either usual care or FFRCT. The number of diagnostic tests, invasive procedures, hospitalizations, and medications during 90-day follow-up were multiplied by U.S. cost weights and summed to derive total medical costs. Changes in QOL from baseline to 90 days were assessed using the Seattle Angina Questionnaire, the EuroQOL, and a visual analog scale.

RESULTS

In the 584 patients, 74% had atypical angina, and the pre-test probability of coronary disease was 49%. In the planned invasive stratum, mean costs were 32% lower among the FFRCT patients than among the usual care patients ($7,343 vs. $10,734 p < 0.0001). In the noninvasive stratum, mean costs were not significantly different between the FFRCT patients and the usual care patients ($2,679 vs. $2,137; p = 0.26). In a sensitivity analysis, when the cost weight of FFRCT was set to 7 times that of computed tomography angiography, the FFRCT group still had lower costs than the usual care group in the invasive testing stratum ($8,619 vs. $ 10,734; p < 0.0001), whereas in the noninvasive testing stratum, when the cost weight of FFRCT was set to one-half that of computed tomography angiography, the FFRCT group had higher costs than the usual care group ($2,766 vs. $2,137; p = 0.02). Each QOL score improved in the overall study population (p < 0.0001). In the noninvasive stratum, QOL scores improved more in FFRCT patients than in usual care patients: Seattle Angina Questionnaire 19.5 versus 11.4, p = 0.003; EuroQOL 0.08 versus 0.03, p = 0.002; and visual analog scale 4.1 versus 2.3, p = 0.82. In the invasive cohort, the improvements in QOL were similar in the FFRCT and usual care patients.

CONCLUSIONS

An evaluation strategy based on FFRCT was associated with less resource use and lower costs within 90 days than evaluation with invasive coronary angiography. Evaluation with FFRCT was associated with greater improvement in quality of life than evaluation with usual noninvasive testing. (Prospective Longitudinal Trial of FFRCT: Outcomes and Resource Impacts [PLATFORM]; NCT01943903).

Transient right internal thoracic arterial graft kink related to respiratory movements: documentation of its existence, relevance and proposed management

In this case report, we provide the first detailed description of an intermittent mechanical kink of a right internal thoracic artery (ITA) graft to the left anterior descending coronary artery secondary to respiratory movements, and its assessment by pressure wire derived fractional flow reserve (FFR). The patient presented with recurrent unstable angina and documented anterior/anterolateral ischemia. Persistent symptoms were attributed to the ITA kink and stenting was planned on clinical grounds. However, the lesion proved not physiologically significant when FFR was assessed after intermittency related to respiratory movements was documented. Complex stenting was therefore avoided and medical therapy was prescribed for distal diagonal disease. We therefore propose that intermittency should be actively investigated when a kink is documented in a coronary bypass graft by conventional angiography (using dedicated angiographic evaluation in maximal inspiration and expiration). Furthermore, when this type of lesion is encountered, we suggest that it should be assessed physiologically using pressure wire derived FFR before potentially complex interventions are considered.