No "a" necessary. It would be nice to have a little more context, but these are catchy titles.

Spanishexperto Free Spanish Lessons - The Past Subjunctive ...
www.spanishexperto.com/free.../the_past_subjunctive_tense.h...
Si (tú) me das diez Euros (yo) lo haré. If you give me ten Euros I will do it. (Yo) gritaré si (tú) no me sueltas. I will shout if you don't let go of me. 1) When talking ...

if you let me go
has other connotations

i.e. let me leave

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Note added at 1 hr (2011-10-17 16:04:35 GMT)
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Soltar = to let go of | Spanish Verb Conjugator
spanishverbconjugator.org/soltar-to-let-go-of/
Spanish Verb Conjugator - The Irregular Spanish Verb Soltar conjugation meaning To Let Go Of. Conjugated in Present, Future and past tenses. Soltar ...

I guess you have more context that leads you to understand that it's about relationships and someone leaving someone else. But without knowing this I'd go more literal as per my answer, which could also fit with the relationship context



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Note added at 1 hr (2011-10-17 16:31:57 GMT)
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the implications of the "other connotations" seem to be fitting given the subject matter of the exhibition posted below by Phil http://tiny.cc/yi6y6

"Si me sueltas, me caigo", refleja la vulnerabilidad de Mónica y su necesidad de sentirse sujetada, mediante la unión, con pequeñas ligas y apretadores, de dos figuras de cartón.

Mónica Reyes indica que el trabajo que presenta es fruto de una instrospección, un autoanálisis en el que no tiene reparo en manifestar su vulnerabilidad, la necesidad de sentirse sostenida y protegida en determinados momentos de la vida.