Importance

Coronary computed tomography angiography (CCTA) is a new approach for the diagnosis of anatomical coronary artery disease (CAD), but it is unclear how CCTA performs compared with the standard approach of functional stress testing.

Objective

To compare the clinical effectiveness of CCTA with that of functional stress testing for patients with suspected CAD.

Data Sources

A systematic literature search was conducted in PubMed and MEDLINE for English-language randomized clinical trials of CCTA published from January 1, 2000, to July 10, 2016.

Study Selection

Researchers selected randomized clinical trials that compared a primary strategy of CCTA with that of functional stress testing for patients with suspected CAD and reported data on patient clinical events and changes in therapy.

Data Extraction and Synthesis

Two reviewers independently extracted data from and assessed the quality of the trials. This analysis followed the PRISMA statement for reporting systematic reviews and meta-analyses and used the Cochrane Collaboration's tool for assessing risk of bias in randomized trials. The Mantel-Haenszel method was used to conduct the primary analysis. Summary relative risks were calculated with a random-effects model.

Main Outcomes and Measures

The outcomes of interest were all-cause mortality, cardiac hospitalization, myocardial infarction, invasive coronary angiography, coronary revascularization, new CAD diagnoses, and change in prescription for aspirin and statins.

Results

Thirteen trials were included, with 10 315 patients in the CCTA arm and 9777 patients in the functional stress testing arm who were followed up for a mean duration of 18 months. There were no statistically significant differences between CCTA and functional stress testing in death (1.0% vs 1.1%; risk ratio [RR], 0.93; 95% CI, 0.71-1.21) or cardiac hospitalization (2.7% vs 2.7%; RR, 0.98; 95% CI, 0.79-1.21), but CCTA was associated with a reduction in the incidence of myocardial infarction (0.7% vs 1.1%; RR, 0.71; 95% CI, 0.53-0.96). Patients undergoing CCTA were significantly more likely to undergo invasive coronary angiography (11.7% vs 9.1%; RR, 1.33; 95% CI, 1.12-1.59) and revascularization (7.2% vs 4.5%; RR, 1.86; 95% CI, 1.43-2.43). They were also more likely to receive a diagnosis of new CAD and to have initiated aspirin or statin therapy.

Conclusions and Relevance

Compared with functional stress testing, CCTA is associated with a reduced incidence of myocardial infarction but an increased incidence of invasive coronary angiography, revascularization, CAD diagnoses, and new prescriptions for aspirin and statins. Despite these differences, CCTA is not associated with a reduction in mortality or cardiac hospitalizations.

The single greatest challenge to an HIV cure is the persistence of latently infected cells containing inducible, replication-competent proviral genomes, which constitute only a small fraction of total or infected cells in the body. Although resting CD4 T cells in the blood are a well-known source of viral rebound, more than 90% of the body's lymphocytes reside elsewhere. Many are in gut tissue, where HIV DNA levels per million CD4 T cells are considerably higher than in the blood. Despite the significant contribution of gut tissue to viral replication and persistence, little is known about the cell types that support persistence of HIV in the gut; importantly, T cells in the gut have phenotypic, functional, and survival properties that are distinct from T cells in other tissues. The mechanisms by which latency is established and maintained will likely depend on the location and cytokine milieu surrounding the latently infected cells in each compartment. Therefore, successful HIV cure strategies require identification and characterization of the exact cell types that support viral persistence, particularly in the gut. In this review, we describe the seeding of the latent HIV reservoir in the gut mucosa; highlight the evidence for compartmentalization and depletion of T cells; summarize the immunologic consequences of HIV infection within the gut milieu; propose how the damaged gut environment may promote the latent HIV reservoir; and explore several immune cell targets in the gut and their place on the path toward HIV cure.