Cochrane · systematic review · CD006612

Homocysteine‐lowering interventions for preventing cardiovascular events

Martí-Carvajal, AJ, Solà, I, Lathyris, D, et al. · Cochrane Database of Systematic Reviews · 2017 · Cochrane Library

Heart4 versionsAMSTAR 2: not assessed

SoF tableOnly the outcomes this review put in its Summary of Findings table are listed (the Cochrane Handbook caps them at about seven per comparison). Its other analyses are not shown here.

Questions

current version

GRADE rated

No studies

Included studies

No studies 2 · 15.4%Ungraded 0 · 0%Very low 1 · 7.7%Low 0 · 0%Moderate 4 · 30.8%High 6 · 46.2%

Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.

Questions and results

Current version only

Homocysteine‐lowering interventions (Vitamin B6 (pyridoxine; pyridoxal); B9 (folic acid) or B12 (cyanocobalamin) compared with placebo or standard care for preventing cardiovascular events

Population: adults at risk of or with established cardiovascular disease

CD006612.PUB5 (current) · 4 questions

Outcome	Effect	Evidence	Status / GRADE
Myocardial infarction Homocysteine‐lowering interventions (Vitamin B6 (pyridoxine; pyridoxal); B9 (folic acid) or B12 (cyanocobalamin) vs placebo or standard care	RR 1.02 [0.95, 1.1]	12 studies · 46699 participants	High
Stroke Homocysteine‐lowering interventions (Vitamin B6 (pyridoxine; pyridoxal); B9 (folic acid) or B12 (cyanocobalamin) vs placebo or standard care	RR 0.9 [0.82, 0.99]	10 studies · 44224 participants	High
Death by any cause Homocysteine‐lowering interventions (Vitamin B6 (pyridoxine; pyridoxal); B9 (folic acid) or B12 (cyanocobalamin) vs placebo or standard care	RR 1.01 [0.96, 1.06]	11 studies · 44817 participants	High
Adverse events Homocysteine‐lowering interventions (Vitamin B6 (pyridoxine; pyridoxal); B9 (folic acid) or B12 (cyanocobalamin) vs placebo or standard care	RR 1.07 [1, 1.14]	8 studies · 35788 participants	High

Homocysteine‐lowering interventions (high dose) compared with homocysteine‐lowering interventions (low dose) for preventing cardiovascular events

Population: adults at risk of or with established cardiovascular disease

CD006612.PUB5 (current) · 4 questions

Outcome	Effect	Evidence	Status / GRADE
Myocardial infarction Homocysteine‐lowering interventions (high dose) vs homocysteine‐lowering interventions (low dose)	RR 0.9 [0.66, 1.23]	1 study · 3649 participants	Moderate Downgraded: imprecision
Stroke Homocysteine‐lowering interventions (high dose) vs homocysteine‐lowering interventions (low dose)	RR 0.9 [0.66, 1.22]	2 studies · 3929 participants	Very low Downgraded: risk of bias, imprecision, inconsistency
Death by any cause Homocysteine‐lowering interventions (high dose) vs homocysteine‐lowering interventions (low dose)	RR 0.86 [0.66, 1.11]	1 study · 3649 participants	Moderate Downgraded: imprecision
Cancer Homocysteine‐lowering interventions (high dose) vs homocysteine‐lowering interventions (low dose)	no estimate extracted	NR	No studies

Enalapril plus folic acid compared with enalapril for adults with hypertension

Population: adults with hypertension

CD006612.PUB5 (current) · 5 questions

Outcome	Effect	Evidence	Status / GRADE
Myocardial infarction Enalapril plus folic acid vs enalapril	RR 1.04 [0.6, 1.82]	1 study · 20702 participants	Moderate Downgraded: imprecision
Stroke Enalapril plus folic acid vs enalapril	RR 0.79 [0.68, 0.93]	1 study · 20702 participants	High
First unstable angina pectoris episode requiring hospitalisation Enalapril plus folic acid vs enalapril	no estimate extracted	NR	No studies
Death from any cause Enalapril plus folic acid vs enalapril	RR 0.94 [0.81, 1.1]	1 study · 20702 participants	High
Serious adverse event (cancer) Enalapril plus folic acid vs enalapril	RR 0.96 [0.71, 1.31]	1 study · 20243 participants	Moderate Downgraded: imprecision

Homocysteine‐lowering interventions (folic acid, vitamin B6 and vitamin B12) compared with placebo or standard care for preventing cardiovascular events

Population: Adults at risk of or with established cardiovascular disease

CD006612.PUB4 · 4 questions

Outcome	Effect	Evidence	Status / GRADE
Non‐fatal or fatal myocardial infarction Homocysteine‐lowering interventions (folic acid, vitamin B6 and vitamin B12) vs placebo or standard care	RR 1.02 [0.95, 1.1]	11 studies · 43290 participants	High
Stroke Homocysteine‐lowering interventions (folic acid, vitamin B6 and vitamin B12) vs placebo or standard care	RR 0.91 [0.82, 1.01]	9 studies · 40815 participants	High
Death from any cause Homocysteine‐lowering interventions (folic acid, vitamin B6 and vitamin B12) vs placebo or standard care	RR 1.01 [0.96, 1.07]	10 studies · 41898 participants	High
Cancer Homocysteine‐lowering interventions (folic acid, vitamin B6 and vitamin B12) vs placebo or standard care	RR 1.06 [0.98, 1.13]	7 studies · 32869 participants	High

Homocysteine‐lowering interventions (Folic Acid, Vitamin B6 and Vitamin B12) compared to placebo or standard care for preventing cardiovascular events

Population: patients with preventing cardiovascular events

CD006612.PUB3 · 4 questions

Outcome	Effect	Evidence	Status / GRADE
Myocardial infarction (non‐fatal or fatal) Homocysteine‐lowering interventions (Folic Acid, Vitamin B6 and Vitamin B12) vs placebo or standard care	RR 1.02 [0.95, 1.1]	10 studies · 43290 participants	High
Stroke Homocysteine‐lowering interventions (Folic Acid, Vitamin B6 and Vitamin B12) vs placebo or standard care	RR 0.91 [0.82, 1.01]	8 studies · 40815 participants	High
Death by any cause Homocysteine‐lowering interventions (Folic Acid, Vitamin B6 and Vitamin B12) vs placebo or standard care	RR 1.01 [0.96, 1.07]	10 studies · 41898 participants	High
Cancer Homocysteine‐lowering interventions (Folic Acid, Vitamin B6 and Vitamin B12) vs placebo or standard care	RR 1.06 [0.98, 1.13]	7 studies · 32869 participants	High

Homocysteine‐lowering treatments for preventing cardiovascular events compared to placebo or standard care

Population: patients with preventing cardiovascular events

CD006612.PUB2 · 4 questions

Outcome	Effect	Evidence	Status / GRADE
Myocardial infarction Homocysteine‐lowering treatments for preventing cardiovascular events vs placebo or standard care	RR 1.03 [0.94, 1.13]	7 studies · 20561 participants	Moderate
Stroke Homocysteine‐lowering treatments for preventing cardiovascular events vs placebo or standard care	RR 0.89 [0.73, 1.08]	5 studies · 18086 participants	Moderate
Death by any cause Homocysteine‐lowering treatments for preventing cardiovascular events vs placebo or standard care	RR 1 [0.92, 1.09]	6 studies · 18679 participants	Moderate
Serious adverse events (Cancer) Homocysteine‐lowering treatments for preventing cardiovascular events vs placebo or standard care	RR 1.06 [0.9, 1.25]	3 studies · 12361 participants	Moderate