The American College of Cardiology Annual Scientific Session (ACC.22) provided a host of new data and results. Focusing on the interventional section, there are four trials that stand out as important, particularly for practicing interventionalists. The following are summaries of each with "Quick Takes" to help focus on the important concepts. I trust these will be useful to enhance your education and practice.

Complete Versus Culprit-Only Revascularization Strategies to Treat Multivessel Disease After Early PCI for STEMI - COMPLETE

Presented by Dr. Shamir R. Mehta at the American College of Cardiology Annual Scientific Session (ACC.22), Washington, DC, April 2, 2022.

Trial Summary:

Study Goal:
To determine the optimal revascularization strategy, culprit only versus complete revascularization, for patients with a STEMI and multivessel coronary disease. The current sub study aimed to specifically determine if symptomatic outcomes favored complete revascularization.

Study Details:
Patients (N=4,041) with STEMI and multivessel disease were randomized to complete (N=2,016 up to 45 days post STEMI) versus culprit only (N=2,025) PCI. The population had a mean age of 62 years (19% female) with diabetes in 19% of patients. Patients with prior coronary bypass were excluded. Non-culprit lesions were either 70% by visual estimate or 50-60% but required a fractional flow reserve (FFR) ≤0.8.

Results:
The primary composite endpoint of cardiovascular death or MI at 3 years was significantly lower in the complete revascularization group (7.8%) versus the culprit only group (10.5%) (p = 0.004).
Secondary outcomes showed significantly less cardiac death, MI, or ischemic driven revascularization with complete revascularization, but no significant difference in bleeding or contrast induced nephropathy.
For the current trial sub-study, quality of life was significantly better based on the SAQ to 3-year follow up for the complete revascularization group (9.8) versus the culprit only group (9.6) (p = 0.003) but this advantage was only seen when non-culprit lesions were ≥80%. At 3-year follow up 12.5% of the complete revascularization patients had angina versus 15.7% in the culprit-only group (p = 0.013).

Summary:
Relative to the current analysis, quality of life was significantly improved by complete revascularization with less angina coupled with a lower late cardiac event rate.

Comment:
Given that ongoing research may establish predictable methods to identify high-risk, non-culprit lesions via intravascular imaging techniques, future non-culprit lesion treatment might be limited to only high-risk plaques.

Reference:

1. Complete Versus Culprit-Only Revascularization Strategies to Treat Multivessel Disease After Early PCI for STEMI – COMPLETE.

Fractional Flow Reserve and Intravascular Ultrasound-Guided Intervention Strategy for Clinical Outcomes in Patients With Intermediate Stenosis – FLAVOUR

Presented by Dr. Bon-Kwon Koo at the American College of Cardiology Annual Scientific Session (ACC.22), Washington, DC, April 4, 2022.

Trial Summary:

Study Goal:
To assess comparative clinical outcomes for patients with an intermediate coronary lesion evaluated via FFR versus IVUS.

Study Details:

• The study included 1,682 patients with 838 randomized to FFR and 844 to IVUS followed for 24 months. The population mean age was 65 years with 29% females. A third of the population was diabetic. Patients had stable coronary artery disease with a 40-70% lesion (defined as an intermediate lesion) amenable to PCI excluding left main or bypass graft target lesions with life expectancy of 2 years or more.
• Treatment definitions included PCI for an FFR of ≤0.8 with an optimal PCI result showing an FFR ≥0.88 while for IVUS PCI was indicated for a minimal luminal area (MLA) ≤3mm2 or >3-4 mm2 and plaque burden >70% with an optimal PCI result MLA ≥5.5 mm2 with stent edge plaque burden ≤55%.

Results:
The composite outcome consisting of all-cause death, MI, or revascularization at 24 months was non-inferior (8.1% in FFR group vs. 8.5% in IVUS group; non-inferior p = 0.015).
There were no differences in secondary outcome at 24 months for MI (FFR 1.9% vs. IVUS 1.7%; p = 0.70), revascularization (FFR 5.7% vs. IVUS 5.3%; p = 0.71) with no difference in the SAQ for patient reported outcomes comparing FFR versus IVUS.

Summary:
The definitions utilized and the patient population evaluating patients with intermediate coronary lesions by FFR or intravascular IVUS yield similar results at 2 years supporting use of either technology for decision making.

Comment:
This study supports use of either FFR or IVUS to assess intermediate lesions. However, given limited operator experience particularly with intravascular IVUS in many cath labs, these results require appropriate training and experience for interventional physicians and cath lab staff to achieve similar, predictable results for whichever technique is used.

Reference:

1. Fractional Flow Reserve and Intravascular Ultrasound-Guided Intervention Strategy for Clinical Outcomes in Patients With Intermediate Stenosis – FLAVOUR

Investigation of Catheter-Based Renal Denervation in Patients With Uncontrolled Hypertension in the Presence of Antihypertensive Medications - SPYRAL HTN-ON MED

Presented by Dr. Felix Mahfoud at the American College of Cardiology Annual Scientific Session (ACC.22), Washington, DC, April 4, 2022.

Trial Summary:

Study Goal:
The SPYRAL HTN-ON MED trial compared renal denervation to a sham control group in patients with uncontrolled BP despite antihypertensive medical therapy to assess the efficacy of renal denervation. This report provides the results at 36 months.

Study Details:
Patients (N=80) were randomized to renal artery denervation (N=38) versus sham (N=42). All patients had uncontrolled BP (150-180 mmHg SBP; diastolic blood pressure [DBP] ≥90 mmHg with-24 hour ambulatory SBP 140-170 mmHg) while on 1-3 antihypertensive drugs (stable dosing for ≥6 weeks). Mean age was 54 years (range 18-80) including 13% females and 13% with diabetes.

The renal denervation procedure aimed to treat all four quadrants in a spiral fashion to the renal artery including branches 3-8 mm in diameter utilizing the Medtronic Symplicity Spyral™ or G3 denervation catheters.

Throughout the study, patients, caregivers, and those assessing BP on antihypertensive treatment were masked to treatment.

Results:

• At 6 months,
  • 24-hour SBP declined 9 mmHg in the renal denervation group versus only a 1.6 mmHg decline in the sham group (p = 0.0051). A decline in 24-hour DBP over 6 months for renal denervation was 6 mmHg compared to a decline of only 1.9 mmHg in the sham group (p = 0.029).
  • Secondary endpoints included significantly greater declines in office systolic and diastolic values.
  • There were no immediate or early adverse events in the renal denervation group.
• Long term results at 36 months,
  • A decline in 24-hour SBP of 18.7 mmHg in the renal denervation group versus a decline of only 8.6 mmHg in the sham group (p=0.004).
  • A decline in office SBP of 20.9 mmHg in the renal denervation group versus a decline of 12.5 mmHg in the sham group (p=0.07).
  • A decline in nighttime SBP 19.3 mmHg in the renal denervation group versus 6.6 mmHg the sham group (p=0.002).

Summary:
The results support the potential benefit of renal denervation to reduce blood pressure. The favorable 3-year results are encouraging relative to a persistent benefit. Likewise, the lack of procedure related adverse events is favorable.

Comment:
This study is encouraging as the impact of relatively small reductions in blood pressure are associated with significant adverse vascular events. However, the numbers of patients are small but despite the low numbers the variation of age and basic demographics were wide providing hope that the effect may cover a diverse population. Future, larger studies will be necessary to better understand the effectiveness of this therapy relative to different populations but given the significant numbers of patients with inadequately treated BP, these results are encouraging.

References:

1. Investigation of Catheter-Based Renal Denervation in Patients With Uncontrolled Hypertension in the Presence of Antihypertensive Medications - SPYRAL HTN-ON MED.
2. Mahfoud F, Kandazari DE, Kario K, et al. Long-term efficacy and safety of renal denervation in the presence of antihypertensive drugs (SPYRAL HTN-ON MED): a randomized, sham-controlled trial. Lancet 2022;Apr 4:[Epub ahead of print].

Prevention of Radial Artery Occlusion After Transradial Access Using Nitroglycerin – PATENS

Presented by Dr. Roberto da Silva at the American College of Cardiology Annual Scientific Session (ACC.22), Washington, DC, April 2022.

Trial Summary:

Study Goal:
To assess the effectiveness of intra-arterial nitroglycerin versus placebo to prevent radial artery occlusion post-coronary angiography via percutaneous radial artery access.

Study details:
The trial included 2,040 patients (mean age 62 years, 38% female and 37% with diabetes) undergoing coronary angiography via percutaneous radial access who were randomized to receive intra-arterial nitroglycerin 500 mcg (N=1,020) versus placebo (N=1,020). In addition, the timing of treatment initiation was also randomized to administration immediately prior to sheath placement versus just before sheath removal. The mean number of catheter changes was 1.8.

Results:
Radial artery occlusion at 24 hours occurred in 2.5% of the early nitroglycerin group versus 2.3% of the placebo group (p = 0.65) while radial occlusion occurred in 2.3% of the "late" nitroglycerin group and occlusion occurred in 2.5% of the placebo group (p = 0.65) consistent with no effect on intra-arterial nitroglycerin regardless of when administered, early or late.
Radial occlusion at 30 days was present in 1.8% of the nitroglycerin group compared to 1.6% of the placebo group (p = 0.73) again showing no effect of nitroglycerin. Radial artery spasm occurred in 10.8% of the nitroglycerin group versus 13.4% of the placebo group (p = 0.06) suggesting a potentially mild effect. Lastly, hypotensive episodes were significantly more common in the nitroglycerin group (2.5%) versus 1.2% in the placebo group (p = 0.03).

Summary:
This trial demonstrated no benefit for intra-arterial nitroglycerin to prevent radial artery occlusion regardless of the timing of administration. However, in appropriate persons the use of intra-arterial nitroglycerin may help manage spasm but must be done cautiously, as there is an increased risk of drug related hypotension.

Comment:
Thus, nitroglycerin continues as a potential benefit to manage radial artery spasm during coronary angiograph performed percutaneously via the radial artery. However, an increased risk of hypertension is present, although infrequent. Thus, individualized clinical decisions can apply, recognizing that preservation of the radial artery effected by the treatment.

References:

1. Prevention of Radial Artery Occlusion After Transradial Access Using Nitroglycerin – PATENS.
2. da Silva RL, de Andrade PB, Dangas G, et al. Randomized clinical trial on prevention of radial occlusion after transradial access using nitroglycerin: PATENS Trial. JACC Cardiovasc Interv 2022;Mar 21:[Epub ahead of print].