Lower Level of Low Density Lipoprotein Cholesterol is Associated with a Higher Increase in the Fractional Flow Reserve in Patients with Fixed-dose Rosuvastatin

Optimal lipid-lowering therapy in patients who were functionally deferred percutaneous coronary intervention

Deferral of percutaneous coronary intervention (PCI) for functionally insignificant stenosis, defined as fractional flow reserve (FFR) > 0.80, is associated with favorable long-term prognoses. The lower-the-better strategy for low-density lipoprotein cholesterol (LDL-C) management is an established non-angioplasty therapy to improve the clinical outcomes of patients undergoing PCI. We examined the optimal LDL-C management in cases of intermediate coronary stenosis with deferred PCI on the basis of FFR values. This observational study included 273 consecutive patients with a single target vessel and deferred PCI with an FFR > 0.80. Patients with an FFR of 0.81-0.85 (n = 93) and those with FFR > 0.85 (n = 180) were classified into the lower (< 100 mg/dL) and higher (≥ 100 mg/dL) LDL-C groups. The endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), including death, non-fatal myocardial infarction, ischemic stroke, heart failure hospitalization, and unplanned revascularization. Patients with an FFR of 0.81-0.85 had a significantly higher MACCE rate than those with an FFR > 0.85 (log-rank, p = 0.003). In patients with an FFR of 0.81-0.85, the lower LDL-C group showed a significantly lower MACCE rate than the higher LDL-C group (log-rank, p = 0.006). However, the event rate did not differ significantly between the two groups in patients with FFR > 0.85 (log-rank, p = 0.84). Uncontrolled LDL-C levels were associated with higher MACCE rates in cases with deferred PCI due to an FFR of 0.81-0.85. This high-risk population for adverse cardiovascular events should receive strict LDL-C-lowering therapy.

Influence of intensive lipid-lowering on CT derived fractional flow reserve in patients with stable chest pain: Rationale and design of the FLOWPROMOTE study

INTRODUCTION

Coronary CT angiography (CTA) derived fractional flow reserve (FFR_CT ) shows high diagnostic performance when compared to invasively measured FFR. Presence and extent of low attenuation plaque density have been shown to be associated with abnormal physiology by measured FFR. Moreover, it is well established that statin therapy reduces the rate of plaque progression and results in morphology alterations underlying atherosclerosis. However, the interplay between lipid lowering treatment, plaque regression, and the coronary physiology has not previously been investigated.

AIM

To test whether lipid lowering therapy is associated with significant improvement in FFR_CT , and whether there is a dose-response relationship between lipid lowering intensity, plaque regression, and coronary flow recovery.

METHODS

Investigator driven, prospective, multicenter, randomized study of patients with stable angina, coronary stenosis ≥50% determined by clinically indicated first-line CTA, and FFR_CT  ≤ 0.80 in whom coronary revascularization was deferred. Patients are randomized to standard (atorvastatin 40 mg daily) or intensive (rosuvastatin 40 mg + ezetimibe 10 mg daily) lipid lowering therapy for 18 months. Coronary CTA scans with blinded coronary plaque and FFR_CT analyses will be repeated after 9 and 18 months. The primary endpoint is the 18-month difference in FFR_CT using (1) the FFR_CT value 2 cm distal to stenosis and (2) the lowest distal value in the vessel of interest. A total of 104 patients will be included in the study.

CONCLUSION

The results of this study will provide novel insights into the interplay between lipid lowering, and the pathophysiology in coronary artery disease.

Serial changes in the quantitative flow ratio in patients with intermediate residual stenosis after percutaneous coronary intervention

A beneficial surrogate marker for evaluating the effect of medical therapy is warranted to avoid deferred lesion revascularization. Similar to coronary artery imaging for monitoring the effects of medical therapy by analyzing plaque regression and stabilization, we hypothesized that evaluation of serial changes in the quantitative flow ratio (QFR) would serve as a surrogate marker of the effects of medical therapy against deferred lesion revascularization. Here, we investigated serial changes in QFR over time after percutaneous coronary intervention in patients who underwent medical therapy as a secondary prevention. Patients with intermediate stenosis in an untreated vessel observed at the baseline (BL) coronary angiography and follow-up (FU) coronary angiography performed 6-18 months after BL angiography were screened in 2 centers. A total of 52 patients were able to analyze both BL and FU QFR. The median QFR was 0.83 (IQR, 0.69, 0.89) at BL and 0.80 (IQR, 0.70, 0.86) at FU. The number of positive ΔQFR and negative ΔQFR were 21 and 31, respectively. The median ΔQFR was 0.05 (IQR, 0.03, 0.09) in positive ΔQFR and  - 0.05 (IQR,  - 0.07,  - 0.03) in negative ΔQFR (p < 0.0001). Univariate and multivariate analyses revealed that LDL-C at FU predicted improvement in the QFR (OR 0.95, 95% confidence interval [0.91, 0.98], P = 0.001). Assessment of serial changes in the QFR may serve as a surrogate marker for the effects of medical therapy in patients with residual intermediate coronary stenosis.

Effect of Low-Density Lipoprotein Cholesterol Goal Achievement on Vascular Physiology Evaluated by Quantitative Flow Ratio in Patients Who Underwent Percutaneous Coronary Intervention

Purpose: The change in coronary physiology from lipid-lowering therapy (LLT) lacks an appropriate method of examination. Quantitative flow ratio (QFR) is a novel angiography-based approach allowing rapid assessment of coronary physiology. This study sought to determine the impact of low-density lipoprotein cholesterol (LDL-C) goal achievement on coronary physiology through QFR. Methods: Cases involving percutaneous coronary intervention (PCI) and 1-year angiographic follow-up were screened and assessed by QFR analysis. Patients were divided into two groups according to the LDL-C level at the 1-year follow-up: (1) goal-achievement group (LDL-C < 1.8 mmol/L or reduction of ≥50%, n = 146, lesion = 165) and (2) non-achievement group (n = 286, lesion = 331). All QFR data and major adverse cardiovascular and cerebrovascular events (MACCEs) at 1 year were compared between groups. Results: No differences between the groups in quantitative coronary angiography (QCA) data or QFR post-PCI were found. At the 1-year follow-up, lower percentage diameter stenosis (DS%) and percentage area stenosis (AS%) were recorded in the goal-achievement group (27.89 ± 10.16 vs. 30.93 ± 12.03, p = 0.010, 36.57 ± 16.12 vs. 41.68 ± 17.39, p = 0.003, respectively). Additionally, a better change in QFR was found in the goal-achievement group (0.003 ± 0.068 vs. -0.018 ± 0.086, p = 0.007), with a lower incidence of physiological restenosis and MACCEs (2.1 vs. 8.4%, p = 0.018, 5.4 vs. 12.6%, p = 0.021, respectively). Conclusion: Evaluated by QFR, patients who achieved the LDL-C goal appear to have a better coronary physiological benefit. This group of patients also has a better clinical outcome.

Coronary flow impairment in asymptomatic patients with early stage type-2 diabetes: Detection by FFRCT

PURPOSE

To determine the occurrence of physiological significant coronary artery disease (CAD) by coronary CT angiography (CTA) derived fractional flow reserve (FFRCT) in asymptomatic patients with a new diagnosis (<1 year) of type-2 diabetes mellitus (T2DM).

METHODS

FFRCT-analysis was performed from standard acquired coronary CTA data sets. The per-patient minimum distal FFRCT-value (d-FFRCT) in coronary vessels (diameter ⩾1.8 mm) was registered. The threshold for categorizing FFRCT-analysis as abnormal was a d-FFRCT ⩽0.75. Total plaque volume and volumes of calcified plaque, non-calcified plaque, and low-density non-calcified plaque (LD-NCP) were assessed by quantitative plaque analysis.

RESULTS

Overall, 76 patients; age, mean (SD): 56 (11) years; males, n (%): 49(65), were studied. A total of 57% of patients had plaques. The d-FFRCT was ⩽0.75 in 12 (16%) patients. The d-FFRCT, median (IQR), was 0.84 (0.79-0.87). Median (range) d-FFRCT in patients with d-FFRCT ⩽0.75 was 0.70 (0.6-0.74). Patients with d-FFRCT⩽0.75 versus d-FFRCT >0.75 had numerically higher plaque volumes for all plaques components, although only significant for the LD-NCP component.

CONCLUSION

Every sixth asymptomatic patient with a new diagnosis of T2DM has hemodynamic significant CAD as evaluated by FFRCT. Flow impairment by FFRCT was associated with coronary plaque characteristics.