Vessel-Specific Outcomes of Deferred Revascularization Following Negative Fractional Flow Reserve

Variations in myocardial supply area and hydrostatic pressure gradients result in greater likelihood of positive fractional flow reserve (FFR) in the left anterior descending (LAD) compared with the circumflex (Cx) and right coronary artery (RCA). However, the same FFR threshold for deferral of revascularization is applied to all arteries, without evidence that this results in equivalent outcomes. We assessed vessel-specific outcomes of deferred revascularization for the 3 major coronary arteries based on FFR > 0.8. In this retrospective study, data were obtained on consecutive patients who underwent indicated FFR assessment across 2 tertiary institutions. Patients with deferred revascularization were followed for 36 months for the primary end point of vessel-specific target lesion failure (TLF). Of 1,916 major coronary arteries (1,579 patients), the odds ratio of positive FFR was highest in the LAD (odds ratio 3.36, p <0.001). In total, 867 vessels (733 patients) with FFR > 0.8 had complete 3-year medical record follow-ups. The TLF rate for deferred vessels was 10.21%, 11.52%, and 10.96% for the LAD, Cx, and RCA respectively. In a multivariate analysis, there was no significant difference in the odds of TLF for the 0.84 (0.53 to 1.33, p = 0.459), 1.17 (0.68 to 2.01, p = 0.582), and 1.11 (0.62 to 2.00, p = 0.715) in the LAD, Cx, and RCA, respectively. In a multivariate analysis, diabetes mellitus was the only baseline characteristic significantly associated at risk of TLF (1.43 [1.01 to 2.02], p = 0.043). In conclusion, despite greater likelihood of positive FFR in the LAD, the FFR threshold for deferred revascularization resulted in equivalent outcomes in all 3 major coronary arteries, and patients with diabetes mellitus may represent a group that requires aggressive surveillance and risk factor modification after deferred revascularization.

Prospective observational study on the accuracy of predictors of high-grade atrioventricular conduction block after transcatheter aortic valve implantation (CONDUCT-TAVI): study protocol, background and significance

INTRODUCTION

Aortic stenosis is the most common cardiac valve pathology worldwide and has a mortality rate of over 50% at 5 years if left untreated. Transcatheter aortic valve implantation (TAVI) is a minimally invasive and highly effective alternative treatment option to open-heart surgery. High-grade atrioventricular conduction block (HGAVB) is one of the most common complications after TAVI and requires a permanent pacemaker. Due to this, patients are typically monitored for 48 hours post TAVI, however up to 40% of HGAVB may delayed, and occur after discharge. Delayed HGAVB can cause syncope or sudden unexplained cardiac death in a vulnerable population, and no accurate methods currently exist to identify patients at risk.

METHODS AND ANALYSIS

The prospective observational study on the accuracy of predictors of high-grade atrioventricular conduction block after transcatheter aortic valve implantation (CONDUCT-TAVI) trial is an Australian-led, multicentre, prospective observational study, aiming to improve the prediction of HGAVB, after TAVI. The primary objective of the trial is to assess whether published and novel invasive electrophysiology predictors performed immediately before and after TAVI can help predict HGAVB after TAVI. The secondary objective aims to further evaluate the accuracy of previously published predictors of HGAVB after TAVI, including CT measurements, 12-lead ECG, valve characteristics, percentage oversizing and implantation depth. Follow-up will be for 2 years, and detailed continuous heart rhythm monitoring will be obtained by inserting an implantable loop recorder in all participants.

ETHICS AND DISSEMINATION

Ethics approval has been obtained for the two participating centres. Results of the study will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ACTRN12621001700820.

Outcomes of deferred revascularisation following negative fractional flow reserve in diabetic and non-diabetic patients: a meta-analysis

BACKGROUND

Fractional Flow Reserve (FFR) is a widely applied invasive physiological assessment, endorsed by major guidelines to aid in the decision to perform or defer revascularisation. While a threshold of  > 0.8 has been applied universally, clinical outcomes may be affected by numerous factors, including the presence of diabetes. This meta-analysis aims to investigate the outcomes of diabetic versus non-diabetic patients in whom revascularisation was deferred based on negative FFR.

METHODS

We performed a meta-analysis investigating the outcomes of diabetic and non-diabetic patients in whom revascularisation was deferred based on negative FFR. A search was performed on MEDLINE, PubMed and EMBASE, and peer-reviewed studies that reported MACE for diabetic and non-diabetic patients with deferred revascularisation based on FFR  > 0.8 were included. The primary end point was MACE.

RESULTS

The meta-analysis included 7 studies in which 4275 patients had revascularisation deferred based on FFR > 0.8 (1250 diabetic). Follow up occurred over a mean of 3.2 years. Diabetes was associated with a higher odds of MACE (OR = 1.66, 95% CI 1.35-2.04, p =  < 0.001), unplanned revascularisation (OR = 1.48, 95% CI 1.06-2.06, p = 0.02), all-cause mortality (OR = 1.74, 95% CI 1.20-2.52, p = 0.004) and cardiovascular mortality (OR = 2.08, 95% CI 1.07-4.05, p = 0.03).

CONCLUSIONS

For patients with stable coronary syndromes and deferred revascularisation based on FFR > 0.8, the presence of diabetes portends an increased long-term risk of MACE compared to non-diabetic patients. Trail registration URL:  https://www.crd.york.ac.uk/PROSPERO/ ; Unique identifier: CRD42022367312.