Prognostic value of fractional flow reserve: linking physiologic severity to clinical outcomes.

BACKGROUND: Fractional flow reserve (FFR) has become an established tool for guiding treatment, but its graded relationship to clinical outcomes as modulated by medical therapy versus revascularization remains unclear. OBJECTIVES: The study hypothesized that FFR displays a continuous relationship between its numeric value and prognosis, such that lower FFR values confer a higher risk and therefore receive larger absolute benefits from revascularization. METHODS: Meta-analysis of study- and patient-level data investigated prognosis after FFR measurement. An interaction term between FFR and revascularization status allowed for an outcomes-based threshold. RESULTS: A total of 9,173 (study-level) and 6,961 (patient-level) lesions were included with a median follow-up of 16 and 14 months, respectively. Clinical events increased as FFR decreased, and revascularization showed larger net benefit for lower baseline FFR values. Outcomes-derived FFR thresholds generally occurred around the range 0.75 to 0.80, although limited due to confounding by indication. FFR measured immediately after stenting also showed an inverse relationship with prognosis (hazard ratio: 0.86, 95% confidence interval: 0.80 to 0.93; p < 0.001). An FFR-assisted strategy led to revascularization roughly half as often as an anatomy-based strategy, but with 20% fewer adverse events and 10% better angina relief. CONCLUSIONS: FFR demonstrates a continuous and independent relationship with subsequent outcomes, modulated by medical therapy versus revascularization. Lesions with lower FFR values receive larger absolute benefits from revascularization. Measurement of FFR immediately after stenting also shows an inverse gradient of risk, likely from residual diffuse disease. An FFR-guided revascularization strategy significantly reduces events and increases freedom from angina with fewer procedures than an anatomy-based strategy.

Discard first tube for coagulation testing.

Tissue thromboplastin may contaminate the first tube sample due to the trauma of the venipuncture, and therefore, affect the accuracy of coagulation testing. This practice was stopped by Clinical and Laboratory Standards Institute after several studies. However, most of the studies have verified these conclusions and refuted the need for a discard tube when drawing samples for coagulation tests in healthy groups. The purpose of our study was to evaluate the clinical importance of discarding a tube for prothrombin time (PT) determinations on large samples with international normalized ratio (INR) values between and over targeted therapeutic range. Patients receiving oral anticoagulation therapy (OAT) managed by our cardiology service were selected for this study. Tube 1 was always treated as the discard tube. Tube 2 was allocated to be analyzed along with the tube 1 for coagulation tests. Individual values were grouped into four cohorts according to the INR range. The ranges were as follows: less than 2.0, 2.1-3.0, 3.1-4.5 and more. Three hundred and seventy-six samples were drawn for PT/INR and activated partial thromboplastin time testing. We found statistically significant differences between tube 1 and tube 2 (P < 0.05), and satisfactory correlation coefficients were obtained by linear regression analysis (0.86 or greater in all cases). This study consisted of a high number of samples. Our data suggest that drawing a discard tube is still necessary for coagulation testing. Consideration should be given to revising the international guidelines related to the necessity of a discard tube for repeated evaluation of coagulation tests especially receiving long-term OAT.

Relationship between carotid intima-media thickness and coronary angiographic findings: a prospective study.

BACKGROUND: Since cardiovascular diseases are associated with high mortality and generally undiagnosed before the onset of clinical findings, there is a need for a reliable tool for early diagnosis. Carotid intima-media thickness (CIMT) is a non-invasive marker of coronary artery disease (CAD) and is widely used in practice as an inexpensive, reliable, and reproducible method. In the current study, we aimed to investigate prospectively the relationship of CIMT with the presence and extent of significant coronary artery narrowing in patients evaluated by coronary angiography for stable angina pectoris. METHODS: One hundred consecutive patients with stable angina pectoris and documented ischemia on a stress test were included in the study. The patients were divided into two groups according to the result of the coronary angiography: group 1 (39 patients) without a noncritical coronary lesion, and group 2 (61 patients) having at least one lesion more than 50% within the main branches of the coronary arteries. All of the patients underwent carotid Doppler ultrasound examination for measurement of the CIMT by a radiologist blinded to the angiographic data. RESULTS: The mean CIMT was 0.78 +/- 0.21 mm in Group 1, while it was 1.48 +/- 0.28 mm in Group 2 (p = 0.001). The mean CIMT in patients with single vessel disease, multi-vessel disease, and left main coronary artery disease were significantly higher compared to Group 1 (1.2 +/- 0.34 mm, p = 0.02; 1.6 +/- 0.32 mm, p = 0.001; and 1.8 +/- 0.31 mm, p = 0.0001, respectively). Logistic regression analysis identified CIMT (OR 4.3, p < 0.001) and hypertension (OR 2.4, p = 0.04) as the most important factors for predicting CAD. CONCLUSIONS: The findings of this study show that increase in CIMT is associated with the presence and extent of CAD. In conclusion, we demonstrated the usefulness of carotid intima-media thickness in predicting coronary artery disease but large-scale studies are required to define its role in clinical practice.